DE102019132014A1 - Method for producing a shelf from a prefabricated metal plate - Google Patents

Abstract

A method is proposed for producing a shelf which is composed of - a plate (1) with two transverse edges (6) and two longitudinal edges (3), - an end wall (7) on each transverse edge (6), - hollow chambers (11) 12), which extend along the longitudinal edges (3) over the length thereof and are designed as closed profile cross-sections, the profile cross-sections being connected to the top by an edge strip (15) of the plate (1) and to the outside by one connected to the end walls (7) The method is characterized by the steps carried out in any order, forming each hollow chamber (11, 12) by folding the metal plate on the respective longitudinal edge (3) and by at least one further folding on a line parallel to the longitudinal edge ( 3); Forming the end walls (7) by folding the metal plate at the respective transverse edge (6); Folding of tabs (4A, 17A) formed at the ends of the hollow chambers (11, 12) up to their parallel contact with the respective end wall (7); as well as the subsequent steps of subjecting the metal plate to a non-plastic deformation caused by the exertion of force, during which With the plate (1) bulging, the two hollow chambers (11, 12) rotate in opposite directions about their longitudinal axes (A11, A12); Establishing a rigid connection of the straps (4A, 17A) with the respective end wall (7) while maintaining the exertion of force, then ending the exertion of force.

Description

• - einer mit ihrer Oberseite eine rechteckige Warenlagerfläche bildenden Platte mit zwei Querrändern und zwei Längsrändern,
• - einer Stirnwand an jedem Querrand,
• - Hohlkammern, die sich entlang der Längsränder über deren Länge erstrecken und als geschlossene Profilquerschnitte ausgebildet sind, wobei die Profilquerschnitte nach oben durch einen Randstreifen der Platte und nach außen durch eine mit den Stirnwänden verbundene Außenwand begrenzt sind.

The invention relates to a method for producing a shelf from a prefabricated metal plate, the finished shelf being composed of

• - a plate with two transverse edges and two longitudinal edges forming a rectangular goods storage area with its upper side,
• - an end wall on each transverse edge,
• - Hollow chambers which extend along the longitudinal edges over their length and are designed as closed profile cross-sections, the profile cross-sections being limited upwards by an edge strip of the plate and outwards by an outer wall connected to the end walls.

Such shelves are widely used as shelves for the purpose of goods storage, eg. B. in large rack stores or in picking stores. Corresponding to this use, the shelves or shelves are produced in large numbers, which lowers the production costs for the individual floor.

Each shelf consists of a single metal plate, prefabricated by punching. This is then shaped into a shelf using various bending processes. After all punching and bending processes have been completed, a material or force-locking connection process is usually only required in the corner area of the shelf, for example by riveting or pressing in the corner area of the front wall with the outer wall.

Because of the large number of pieces, a primary goal in production is to save material by using prefabricated metal plates with a thin sheet metal. However, thin-walled panels are also less stable, which is why the shelf bases sufficient for storing goods are achieved primarily through suitable stiffening measures. For this purpose z. B. along the longitudinal edges of the sheet metal areas there are not only folded once, but several times. A particularly high level of longitudinal rigidity is achieved by folding the longitudinal edges twice or even three times, with the result that closed hollow chambers are formed along the longitudinal edges that extend over the entire length of the shelf and significantly stiffen it along its two longitudinal edges . Due to the hollow chambers extending along the longitudinal edges, a high level of flexural rigidity is therefore achieved in the longitudinal direction of the shelf, which is also required by standards that apply to shelf technology.

However, there is a problem, especially with high loads in connection with thin-walled metal sheets, in the bending stiffness in the transverse direction. With high weight loads of the stored goods, the plate can sag slightly in the shape of a channel. This can be counteracted somewhat by means of end walls, but the stiffening that can be achieved via the end walls is mainly limited to the two end areas of the shelf, while the shelf tends to sag over the greater part of its total length.

The invention is based on the object of providing a technical solution to this problem and at least achieving improved dimensional stability of the shelf in relation to a channel-shaped bending. A suitable manufacturing process is to be proposed.

A method with the features of claim 1 is proposed to solve this problem.

• - einer mit ihrer Oberseite eine rechteckige Warenlagerfläche bildenden Platte mit zwei Querrändern und zwei Längsrändern,
• - einer Stirnwand an jedem Querrand,
• - Hohlkammern, die sich entlang der Längsränder über deren Länge erstrecken und als geschlossene Profilquerschnitte ausgebildet sind, wobei die Profilquerschnitte nach oben durch einen Randstreifen der Platte und nach außen durch eine mit den Stirnwänden verbundene Außenwand begrenzt sind.

The production method according to the invention is used for shelves made from metal plates prefabricated by punching. The finished shelf consists of

• - a plate with two transverse edges and two longitudinal edges forming a rectangular goods storage area with its upper side,
• - an end wall on each transverse edge,
• - Hollow chambers which extend along the longitudinal edges over their length and are designed as closed profile cross-sections, the profile cross-sections being limited upwards by an edge strip of the plate and outwards by an outer wall connected to the end walls.

• Formung jeder Hohlkammer durch Abkanten der Metallplatte an dem jeweiligen Längsrand und durch mindestens ein weiteres Abkanten an einer Linie parallel zu dem Längsrand;
• Formung der Stirnwände durch Abkanten der Metallplatte an dem jeweiligen Querrand;
• Abkanten von an den Enden der Hohlkammern ausgebildeten Laschen bis zu deren paralleler Anlage an der jeweiligen Stirnwand.

As part of the process, the following steps are initially carried out in any order:

• Forming each hollow chamber by folding the metal plate on the respective longitudinal edge and by at least one further folding on a line parallel to the longitudinal edge;
• Forming the end walls by folding the metal plate at the respective transverse edge;
• Folding of tabs formed at the ends of the hollow chambers up to their parallel contact with the respective end wall.

• Unterziehen der Metallplatte einer durch Kraftausübung hervorgerufenen, nicht-plastischen Verformung, bei der, unter Aufwölbung der Platte, die beiden Hohlkammern gegensinnig um ihre Längsachsen drehen;
• Unter Aufrechterhalten der Kraftausübung Herstellen einer starren Verbindung der Laschen mit der jeweiligen Stirnwand, anschließend Beenden der Kraftausübung.

This is followed by the following steps:

• Subjecting the metal plate to a non-plastic deformation caused by the exertion of force, during which, with the plate bulging, the two hollow chambers rotate in opposite directions about their longitudinal axes;
• While maintaining the exertion of force, establish a rigid connection between the straps and the respective end wall, then end the exertion of force.

The shelf produced in this way is characterized by the fact that it is permanently under tension. This prestressing caused by the non-plastic, i.e. elastic deformation of the metal plate, exists in the transverse direction, i. H. across the length of the shelf. The shelf has a greater extent in its longitudinal direction than in its transverse direction.

The prestress impressed on the shelf in connection with an opposite rotation of the two hollow chambers leads to the plate bulging upwards. When looking in the longitudinal direction of the shelf, the plate can have a slightly curved cross-section. The deformation thus impressed on the shelf increases the dimensional stability of the shelf, namely its resistance to deformation caused by high weight loads. It is true that the forced arching is somewhat reduced with corresponding weight loads, but due to the pre-deformation, the cross-section then established shows an essentially flat contour, and not a groove-shaped, lowered contour.

Advantageous refinements of the method are given in the subclaims.

Thus, one embodiment of the method provides for two tabs formed at each end of the hollow chamber, both of which are bent until they are parallel to the end wall. Preferably, the first tab is rigidly connected to the front wall and the second tab is only rigidly connected to the end wall when the force is exerted.

An embodiment of the method is advantageous in which the second tab is connected to the end wall at a location which is offset in the transverse direction to the location at which the first tab is connected to the end wall.

For an optimal position of the straps to achieve the preload, it is advantageous if the closed profile cross-section of the hollow chamber is delimited downwards by a base and inwards by an inner wall, and if one of the two straps is at the end of the inner wall and the other of the two tabs is formed at the end of the outer wall and is folded. The folding of the tabs on and from the inner wall and on and from the outer wall leads to greater stability during the subsequent connection of the tabs to the end wall. Such a high level of stability could not be achieved with tabs that were only formed on the edge strip of the plate and / or on the floor.

For permanent pretensioning of the shelf, it is also advantageous if the tab formed at the end of the outer wall is connected to the end wall before the force is exerted, whereas the tab formed at the end of the inner wall is connected to the end wall while the force is being applied.

According to a further development of the method, the tab formed at the end of the inner wall is folded so that it extends towards the longitudinal center line of the shelf.

It is advantageous for the dimensional stability of the hollow chambers and thus also the dimensional stability of the shelf base if the bevel of the inner wall relative to the floor is less than 90 ° and preferably below 30 ° -60 °. In this case, the width of the tab formed on the inner wall, starting from its fold, should increasingly decrease.

It is also advantageous if the tab formed at the end of the outer wall is folded so that it extends towards the longitudinal center line of the shelf.

It is also advantageous if the shaping of the end walls, in addition to their folding at the respective transverse edge, takes place by at least one further folding along a line parallel to the transverse edge. This measure leads to an increased strength of the end walls. Since it is precisely the end walls that maintain the pretensioning in the shelf, this measure contributes to permanently securing the pretensioning in the shelf.

Finally, it is advantageous if the rigid connection of the tabs to the respective end wall is carried out by riveting or pressing together.

• 1: in perspektivischer Ansicht einen Regalboden, oft auch als Fachboden bezeichnet;
• 2: ein Metallblech in Gestalt eines in einem Stanzprozess gefertigten Zuschnitts, aus dem anschließend der Regalboden durch Biegeprozesse geformt wird;
• 3: in einer perspektivischen Ansicht von schräg unten einen Teil des Regalbodens in einem Prozessstadium, in dem einzelne Biegeprozesse bereits durchgeführt sind und andere noch nicht;
• 4: dieselbe Ansicht wie 2, in einem weiter fortgeschrittenen Prozessstadium;
• 5: dieselbe Ansicht wie 2 und 3, in einem nochmals weiter fortgeschrittenen Prozessstadium;
• 6: den Regalboden in einem Querschnitt.

Further advantages and details of the method emerge from the associated figures, which are also referred to in more detail below. Show in it:

• 1 : in a perspective view a shelf, often also referred to as a shelf;
• 2 : a sheet of metal in the form of a blank made in a stamping process from which then the shelf is shaped by bending processes;
• 3rd : in a perspective view obliquely from below a part of the shelf in a process stage in which individual bending processes have already been carried out and others have not yet;
• 4th : same view as 2 , at a more advanced stage of the process;
• 5 : same view as 2 and 3rd , in an even more advanced stage of the process;
• 6th : the shelf in a cross-section.

The in 1 from diagonally above and into the 3rd - 5 Shelf shown diagonally below serves as a goods storage area and is used, for. B. in extensive rack warehouses or order picking warehouses as a shelf application. The shelf originally consists of a single in 2 reproduced blank in the form of a contoured metal plate. This is produced in a preliminary process, for example by punching a sheet of steel. The metal plate or the blank is then transformed into the shelf in individual deformation steps, each of which is a bending process 1 deformed.

In the 2 all bending lines on which the bending of the sheet metal, also referred to below as folding, takes place, are shown as dash-dotted lines. Unless expressly stated otherwise, the bending or folding takes place at a folding angle of 90 °.

The in 1 Shelf shown in the finished state has a large plate 1 that with their top 2 forms a goods storage area which is rectangular and of greater length than width. To reinforce the relatively thin-walled plate 1 , the z. B. has a wall thickness of 0.5 mm, outer walls are an integral part of the shelf 4th along the longitudinal edges 3rd the plate, and end walls 7th along the transverse edges 6th the plate. The outside walls 4th and end walls 7th are each right-angled folds along the longitudinal edges 3rd or the transverse margins 6th .

For longitudinal reinforcement, the shelf is along the length of its first longitudinal edge 3rd and along the length of its second longitudinal edge 3rd each with a hollow chamber made by folding the sheet metal several times 11 or. 12th Mistake. The hollow chambers 11 , 12th are profiles of closed and preferably trapezoidal profile cross-section.

Each hollow chamber is in the profile cross-section 11 , 12th to the outside through the outer wall 4th limited downwards by a floor 16 and inwards, i.e. to the longitudinal center line M. of the shelf through an inner wall 17th . Up is the hollow chamber through the plate 1 itself limited, namely by an edge strip 15th ( 2 ) of the rectangular plate 1 .

The profile cross-sections of the two hollow chambers 11 , 12th are to the longitudinal center line M. of the shelf symmetrically arranged and designed.

At an angle to the plate 1 arranged inner wall 17th borders, parallel to this, another narrow connecting strip 18th on which one, around the profile cross-sections of the hollow chambers 11 , 12th to close over its entire circumference, against the underside 20th the plate 1 is stapled, e.g. B. in a soldering or gluing process.

While the outside 4th perpendicular to the plate 1 is arranged is the bottom 16 parallel to the plate 1 arranged. The inner wall 17th is oblique to the ground 16 folded, preferably at an angle of between 30 ° and 60 °. This is how every hollow chamber is 11 , 12th trapezoidal cross-section, which is advantageous for the transverse stability of the shelf.

For transverse reinforcement, the shelf is along each of the transverse edges 6th each with an end wall made by folding 7th Mistake. For further improved reinforcement in the transverse direction, the folding is also carried out on the transverse edge 6th a second folding on a line parallel to the transverse edge 6th , as well as a third folding on another parallel line. As a result of the triple folding, each end wall has, at least over a central part of its total length, a cross section comprising four walls, which, however, differs from the cross section of the hollow chambers 11 , 12th , is not completely closed.

According to 1 are the two end walls 7th of such length that they are in the corner of the plate 1 a right angle with the adjacent exterior walls 4th form.

According to 2 the metal plate is designed so that the later outer walls 4th in each case at their ends, i.e. over the length of the longitudinal edges 3rd addition, extensions 4A exhibit. These extensions are folded once as part of the bending process, and then each form one from the end of the outer wall 4th tab protruding at right angles 4A . The direction of this fold is such that the flap is 4A to the longitudinal centerline M. extends towards ( 4th ). The tab 4A is after completion of all bending processes ( 5 ) from the inside flat against the front wall 7th so that they are firmly attached to the front wall in a process to be described below 7th can be connected.

The 3rd shows the tabs 4A before their bending. In contrast, the 4th the tabs that have been bent inwards by 90 ° 4A . The tabs 4A have a rectangular shape here.

Also the later interior walls 17th point at their ends, i.e. over the length of the longitudinal edges 3rd addition, extensions 17A on. These extensions are edged once during the bending process and then each form one from the end of the inner wall 17th tab protruding at right angles 17A . The direction of this fold is such that the flap is 17A to the longitudinal centerline M. extends towards ( 4th ). The tab 17A is after completion of all bending processes ( 5 ) from the inside flat against the front wall 7th so that they are firmly attached to the front wall in a process to be described below 7th can be connected.

The 3rd shows the tabs 17A before their bending. In contrast, the 4th the tabs that have been bent inwards by 90 ° 17A . The one on the inside wall 17th trained tabs 17A point, other than the tabs 4A , no rectangular shape. Instead, the width of the flaps is reduced 17A , starting from their fold, increasingly.

The rigid connection of the so at all ends of the hollow chambers 11 , 12th trained tabs 4A , 17A with the respective front wall 7th and, above all, the point in time at which these connections are created is of decisive importance in the context of the manufacturing process described here.

The connection of the tabs 4A , 17A with the respective front wall 7th takes place selectively by riveting, stapling or pressing together. Connection by stapling is preferred.

In the 4th and 5 is the connection point 4B on which the tab 4A against the front wall 7th is stapled. Also in the 4th and 5 is the connection point 17B on which the tab 17A against the inside of the front wall 7th is stapled.

First, after all bending processes have been completed, at the four connection locations 4B stapled, i.e. the connection between the flaps 4A and the end walls 7th produced.

The metal plate is then subjected to non-plastic deformation by exerting a force. This deformation causes the plate to bulge 1 in connection with a turning of the two hollow chambers 11 , 12th around longitudinal axes A11 , A12 . It is sufficient for the desired deformation if the two hollow chambers 11 , 12th only rotate relative to each other by z. B. only rotates one hollow chamber, and the other does not. It is important, however, that the rotation or the relative rotation take place in opposite directions. The in 6th reproduced angle of rotation W. is not very large, and it is preferably less than 5 °.

With the twisting of the hollow chambers 11 , 12th around longitudinal axes A11 , A12 is a slight bulging of the plate 1 connected to the top. A twisting of the hollow chambers 11 , 12th can e.g. B. can be actively achieved by first attaching gripping jaws to the hollow chambers, and the gripping jaws are then rotated in opposite directions relative to each other. The top 2 the plate takes a slightly curved course when looking in the longitudinal direction of the shelf. In this state and while maintaining the exertion of force, it is only then at the connection points 17B stapled, i.e. the rigid connection between the tabs 17A and the inside of the end walls 7th produced. Only when this has also happened is the exertion of force stopped.

The deformation caused by the exertion of force is at least partially retained, so that the shelf will also have the deformation that was impressed on it in the future. This deformation increases the dimensional stability of the shelf, namely its resistance to deformation caused by high weight loads. Although the impressed curvature is somewhat reduced with corresponding weight loads, due to the pre-deformation, however, the cross-section then established shows an essentially flat contour and in any case no channel-shaped lowered contour.

The second tab 17A is in one place with the bulkhead 7th connected, which is offset in the transverse direction to the location at which the first tab 4A is connected to the front wall.

It is advantageous if the stapling is done at the connection points further out 4B before the exertion of force, and stapling at the connection locations further inwards 17B is carried out after or during the exercise of force.

In order for the stapling process to the connection location 4B to get is the bottom 16 , adjacent to the front wall 7th , with a sufficiently large opening 23 Mistake. The opening 23 is the result of the stamping process of the sheet metal plate.

List of reference symbols

1

plate

2

Top

3

Longitudinal edge

4th

Outer wall

4A

Tab, extension

4B

Connection location

6th

Transverse edge

7th

Front wall

11

Hollow chamber

12th

Hollow chamber

15th

Edge strips of the plate

16

ground

17th

Inner wall

17A

Tab, extension

17B

Connection location

18th

Connecting strip

20th

bottom

23

opening

A11

Longitudinal axis

A12

Longitudinal axis

M.

Longitudinal center line of the shelf

W.

Rotation angle

Claims (11)

A method for producing a shelf from a prefabricated metal plate, the finished shelf being composed of - a plate (1) with two transverse edges (6) and two longitudinal edges (3), - an end wall ( 7) on each transverse edge (6), - hollow chambers (11, 12), which extend along the longitudinal edges (3) over their length and are designed as closed profile cross-sections, the profile cross-sections upwards through an edge strip (15) of the plate ( 1) and are limited to the outside by an outer wall (4) connected to the end walls (7), characterized by the steps, carried out in any order, of forming each hollow chamber (11, 12) by folding the metal plate at the respective longitudinal edge (3) and by at least one further folding along a line parallel to the longitudinal edge (3); Forming the end walls (7) by folding the metal plate at the respective transverse edge (6); Bending of tabs (4A, 17A) formed at the ends of the hollow chambers (11, 12) until they are in parallel contact with the respective end wall (7); and the subsequent steps subjecting the metal plate to a non-plastic deformation caused by the exertion of force, in which, with the plate (1) bulging, the two hollow chambers (11, 12) rotate in opposite directions about their longitudinal axes (A11, A12); Establishing a rigid connection of the straps (4A, 17A) with the respective end wall (7) while maintaining the exertion of force, then ending the exertion of force. Procedure according to Claim 1 , characterized by two tabs (4A, 17A) formed at each end of each hollow chamber (11, 12), both of which are folded up to their parallel contact with the end wall (7). Procedure according to Claim 2 , characterized in that the first tab (4A) in front and the second tab (17A) is rigidly connected to the end wall (7) only during the exertion of force. Procedure according to Claim 2 or 3rd , characterized in that the second flap (17A) is connected to the end wall (7) at a location which is offset in the transverse direction to the location at which the first flap (4A) is connected to the end wall (7). Method according to one of the Claims 2 to 4th , characterized in that the closed profile cross-section of the hollow chamber (11, 12) is limited downwards by a bottom (16) and inwards by an inner wall (17), and that one of the two tabs at the end of the inner wall (17), and the other of the two tabs is formed at the end of the outer wall (4) and is folded. Procedure according to Claim 5 , characterized in that the tab (4A) formed at the end of the outer wall (4) is connected to the end wall (7) prior to the application of force, and the tab (17A) formed at the end of the inner wall (17) during the maintenance of the Force exertion is connected to the front wall (7). Procedure according to Claim 5 or 6th , characterized in that the tab (17A) formed at the end of the inner wall (17) is folded so that it extends towards the longitudinal center line (M) of the shelf. Procedure according to Claim 7 , characterized in that the folding of the inner wall (17) with respect to the base (16) takes place at less than 90 ° and preferably 30 ° to 60 °, and that the width of the tab (17A) formed on the inner wall (17), starting from their fold, increasingly reduced. Method according to one of the Claims 4 - 8th , characterized in that the tab (4A) formed at the end of the outer wall (4) is folded so that it extends towards the longitudinal center line (M) of the shelf. Method according to one of the preceding claims, characterized in that the shaping of the end walls (7) takes place in addition to their bending at the respective transverse edge (6) by at least one further bending on a line parallel to the transverse edge (6). Method according to one of the preceding claims, characterized in that the rigid connection of the tabs (4A, 17A) to the respective end wall (7) is carried out by riveting, stapling or pressing together.

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