RU2774715C2 - Method and device for manufacture of ribbed thin-sheet panel - Google Patents

Abstract

FIELD: heat engineering.

SUBSTANCE: invention relates to a method and a device for the manufacture of a ribbed thin-sheet panel; it can be used in structures of recuperative heat exchangers. A ribbed thin-sheet panel is manufactured, which contains base (1) made of a metal sheet and metal ribs (2) welded to it. To weld ribs (2) to base (1), clamping device (3) is used, main working elements of which are support (4) and clamping (5) rails. Ribs are inserted into corresponding grooves of the device. Using a system of eccentric clamps or using screws, clamping rails (5) are tightened, thereby rigidly fixing ribs (2) in the space. A sheet base is mounted, rigidly fixed on one side, and inserted into movable clamps (6) on the other side. The sheet base is tightened. Using CNC machine, ribs (2) are welded to the base through sheet base (1) according to a set program.

EFFECT: invention simplifies the manufacture of large-size flat thin-sheet ribbed panels with sheet ribs, allows for reduction in material consumption of a product and decrease in spoilage in the manufacture.

10 cl, 5 dwg

Description

The invention relates to the field of welding, power engineering, metallurgy, energy-saving technology, can be used in mechanical engineering and engine building, primarily can be used in the design of recuperative heat exchangers as a basic element.

A known method for linear welding of sheets into a welded sheet blank by means of a laser (patent RU No. 2150362, IPC B23K 26/42, B23K 101:16, publ. deformation of at least one of the sheets by crushing the edges in the direction of the other sheet and partially closing the gap between the sheets, while the deformation is carried out with the help of a roller in the area of the sheet adjoining the end surface of the sheet, and the laser beam is directed depending on the position of the gap specified by the deformation.

The known method provides an optimal gap for laser welding from 0.05 to 0.08 mm and allows to obtain high quality welding, which eliminates the need for precise cutting and positioning of sheets.

The disadvantage of the known method is that it can only be used for butt welding of flat sheet blanks. With the T-arrangement of the welded sheets, for example, for welding long sheet ribs located perpendicular to the sheet blank, the known method and device cannot be applied.

A known method of manufacturing a ribbed sheet panel (RF patent No. 2279619, IPC B23K 101/18, F28F 3/02, publ. on the outer side of the base of the panel along the spiral of the ribs and unfolding the resulting ribbed panel to a given radius of curvature, while protrusions are formed on the back side of the base of the panel by forcing the base of the panel with ribs in the process of welding them to the outside.

In a known way, it is possible to produce sheet panels up to 1 mm thick with a certain radius of curvature. However, it is impossible to obtain flat ribbed sheet panels both during the process and after welding by straightening.

A known method for linear butt welding of thin metal sheets (patent RU No. 2432243, IPC B23K 37/04, B23K 26/42, B23K 15/10, publ. 10/27/2011), including installation on a support table, a metal sheet and its vertical fastening by means of a clamping element, installation of the second metal sheet end-to-end with the welded edge of the first sheet, its vertical fixing by means of the second clamping element, horizontal pressure of the second metal sheet until a residual gap of 0.05 mm is formed between the sheets and subsequent laser welding is carried out in a shielding gas by moving the welding heads.

This method makes it possible to obtain large flat metal sheets by welding - prefabricated blanks from individual parts by leveling the edges and minimizing the gap between them, applying vertical and horizontal pressure on the sheet, which improves the quality of welding and reduces warping. However, the implementation of the known method requires complex and expensive equipment. In addition, it is not possible to manufacture a large sheet ribbed panel with a large number of closely spaced sheet ribs using this method.

A utility model is known - a ribbed thin-sheet panel (patent RU No. 193960, IPC B28F 3/06, publ. 11/21/2019), which contains a base made of a metal sheet and metal ribs located on it. The ribs are fixed in molded guide grooves made in the base of the panel. The technical result achieved in the implementation of this utility model was to improve the manufacturability of the ribbed sheet panels. However, when trying to implement the known method for large panels, insurmountable obstacles arose. First of all, this is the complexity and high cost of equipment for forming guides, the need to use high-power equipment and large warpage of the workpiece in all planes after the formation of all guide grooves. In view of this, the implementation of this method with large-sized panels is impossible.

The closest in technical essence and purpose is a method for linear welding of a flat thin-sheet ribbed panel, disclosed in the RF patent for invention No. 2 567 936 (publication date 10.11. B23K 101/18) - prototype. Holes are made on the panel, evenly spaced along the welding lines, and spikes are made on the ribs in the form of protrusions, which are then bent. The ribbed panel is obtained by laser welding the ribs through the panel sheet.

However, during laser welding, the panel sheet can deform under the influence of temperature, as a result of which, during the welding program on a numerically controlled machine, the laser beam passes by the holes made in the panel sheet and the ribs aligned with them. As a result, the percentage of defects increases, the manufacturability of the product decreases.

The technical result is the possibility of manufacturing large-sized flat thin-sheet ribbed panels with sheet ribs, and also simplifies the method for its implementation and allows you to significantly increase productivity and manufacturability, as well as reduce the material consumption of the product. Additional technical results are also achieved, which consist in reducing the amount of marriage during manufacture.

The specified technical result is achieved in a method for linear welding of a flat thin sheet ribbed panel, including installing the panel and ribs in a special device, fixing them and subsequent welding in a shielding gas by moving the welding head, according to the invention,

the ribs are preliminarily rigidly fixed in a predetermined position, then the panel is installed in an arcuate device, fixing it from both sides and pulling it with great force, thereby choosing the gap between the ribs and the panel, after which laser linear welding of the ribs is performed, randomly through the sheet according to a given program panels.

Precise installation of the ribs by locating them in the grooves of the device and their fixation by clamping them in a row of movable rails and the corresponding pairs of fixed rails provide an accurate and rigid position of the ribs in space, both in the horizontal and vertical directions, which helps to reduce panel warpage when welding. At the same time, the tension of the support sheet along the arc with great force allows you to select the vertical gap between the ribs and the panel, to compensate for the change in the size of the base sheet under the thermal action of the laser beam, while the ribs are stationary. All this makes it possible to weld the ribs from the front side through the panel sheet, hitting the middle of the ribs with a laser beam and providing deep penetration and a high-quality sealed seam.

Performing laser welding through a sheet with random stitches of a certain length in two or three passes according to the algorithm embedded in the control device improves heat removal from welded parts, which eliminates warping of a large-sized thin-sheet ribbed panel. Elimination of preliminary tacking of the ribs and the need to melt the protruding part of the studs allows reducing the main welding time and its complexity by several times, while ensuring hermetic welding of the ribs along the entire length. Tightness is due to the exact hit of the laser beam in the middle of the rib and the smooth movement of the welding head without jerks and stops.

Installing the panel in an arcuate device, with a convex outer part, allows the panel to follow the contour of the convex part of the arc, which significantly increases the rigidity of the panel in the transverse direction and reduces its warpage after welding. The finished panel does not have large geometrical defects and is easily released after welding, thanks to the wide locating grooves of the device in the open form.

The technological process consists of only 4 simple parallel operations: 1) cutting a blank sheet on a CNC machine; 2) bending the edges of the base sheet on a CNC machine; 3) removal of the finished previous panel, installation of the ribs and the base sheet into the device; 4) welding of the ribbed panel on a CNC machine.

The proposed sequence of operations of the method allows to produce large-sized ribbed panels from thin metal sheets with high quality by laser welding. At the same time, the manufacturing cycle of one panel, limited by the longest operation - welding, is reduced from 45-60 minutes with the existing method, to 12-15 minutes with this method. Saving machine time equipment is reduced significantly.

The proposed method allows to significantly reduce material consumption and labor costs for the manufacture of finned panels, while maintaining the tightness and reliability of the connection of the rib with the base sheet.

The reduction in material consumption is due to several factors. Along the length of the panel, you can install both solid ribs, and at least divided into two ribs with a compensation gap between them, this allows you to create a denser layout of the ribs along the blank sheet when cutting. It is possible to hermetically weld a base panel from several sheets in the device by means of linear laser butt welding, which saves material when cutting sheets, since the area of a blank sheet is often 30-40% larger than the total area of a solid base sheet and all ribs. Therefore, when cutting with a solid base sheet, only 60-70% of the blank sheet can be used. When cutting, the ribs and the panel have a simple rectangular shape without protrusions and depressions and holes, the contours of the cut parts can be combined, this significantly reduces the cutting time and saves material using the blank sheet area up to 95-100%.

Technical solutions coinciding with the set of essential features of the invention have not been identified, which allows us to conclude that the invention complies with the condition of patentability "novelty".

The claimed essential features of the invention, which predetermine the receipt of the specified technical result, do not explicitly follow from the prior art, which allows us to conclude that the invention complies with the patentability condition "inventive step".

The condition of patentability "industrial applicability" follows from the exemplary embodiment of the invention.

Figure 1 shows a general view of the device.

The figure 2 shows a diagram of the fastening of the ribs and the base sheet.

The figure 3 shows a general view of the device manufactured for testing.

The figure 4 shows the assembled panel during welding on the device.

Figure 5 shows the finished panel in assembled form.

Ribbed sheet panel contains a base (1) made of metal sheet and metal ribs (2) welded to it. To weld the ribs (2) to the base (1), a special clamping device (3) is used, the main working elements of which are the support (4) and clamping (5) rails. The technological process of welding a ribbed panel is as follows: 1) the ribs are inserted into the corresponding grooves of the device; 2) with the help of a system of eccentric clamps or with the help of screws, the clamping rails (5) are tightened, thereby fixing the ribs (2) rigidly in space; 3) a base sheet is installed, rigidly fixed on one side and in floating clamps (6) on the other side; 4) the base sheet is tensioned. 5) using a CNC machine according to a given program, the ribs (2) are welded to the base through the base sheet (1).

Claims (10)

1. A device for installing and fastening ribs and a base sheet for the manufacture of a welded flat thin-sheet ribbed panel, containing arc-shaped slats installed evenly along the welding line on one base, characterized in that some arc-shaped slats are support rails, and others are clamping rails, while the support rails are fixedly fixed, and the clamping rails are movably installed, and the movable clamp rails are placed between the support rails, while the support rails have grooves for basing the panel ribs, which are located along the convex arc at a certain distance from each other, and in the clamping rails are provided with grooves for locating the panel ribs, which are unevenly located along the convex arc and whose position is determined by the extension of the rail in the stretched state at a given load, while the fixed support rails are provided at both ends with elements for fixing and tensioning the base sheet of the panel. 2. The device according to claim 1, characterized in that the grooves in the fixed rails are rectangular in shape, while the width of the grooves is at least twice the thickness of the panel rib. 3. The device according to claim 1, characterized in that the elements for fixing and tensioning the base sheet of the panel are made in the form of clamping eccentric elements or screws. 4. A method for manufacturing a welded flat thin-sheet ribbed panel, including installing a base sheet and ribs in the device according to claims 1-3, fixing them and subsequent welding in a shielding gas by moving a laser welding head, while the ribs are first installed in the corresponding grooves of the fixed rails of the device and using clamping movable rails, the ribs are rigidly fixed in a predetermined position at a certain distance from each other along a convex arc, then the base sheet of the panel is installed over the ribs, fixed on both sides and tensioned, choosing the gap between the ribs and the base sheet, after that, laser linear welding of the ribs is performed according to a given program randomly through the base sheet of the panel. 5. The method according to claim 4, characterized in that during welding, the base sheet of the panel is stretched, leaving the welded ribs immobile. 6. The method according to claim 4, characterized in that the ribs are welded with seams of a given length in two or three passes without preliminary tacking with dots. 7. The method according to claim 4, characterized in that before installing the fins in said device, they are divided into at least two parts, which are then installed with a gap between them. 8. The method according to claim 4, characterized in that the ribs and the base sheet of the panel are cut in the form of rectangular sheets without protrusions, depressions and holes. 9. The method according to claim 4, characterized in that the base sheet of the panel is hermetically welded from several sheets in said device by linear laser butt welding. 10. The method according to claim 4, characterized in that after welding, the finished panel is released from the device.

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