EP1741497B9 - Method and tool for producing without cutting a notch in a workpiece and workpiece with such notch - Google Patents

Abstract

The tool includes a punch (2) and a die. The die has a web (4) in the region of the groove field (6), and a recess (5a, 5b) in the region of the transition from the groove field to at least one side surface. The workpiece (1) produced by the too. has a groove extending at least from top to bottom. The groove should be to a depth of up to 50% of the thickness of the tool, the deeper the better.

Description

The invention relates to a workpiece having a top side and a bottom side and with a non-machined notch, the side surfaces and a notch base, wherein the notch extends at least from the top to the bottom of the workpiece and a method for producing a notch in a workpiece made of metal.

The introduction of notches in workpieces is known in the art. In this case, by this non-machining of workpieces notches in workpieces or in the wall of workpieces, typically z. B. by embossing or rolling generated. As workpieces are in particular those made of metal in question. Typical workpieces are in addition to flat products and pipes.

In known methods for producing non-machined notches z. B. removed by embossing or rolling material from the region of the notch, thereby creating the desired contour. The prior art, however, does not make it possible to form all notches required by designers. Especially deep notches and notches with approximately U-shaped geometry can not be produced with satisfactory quality. Such profiles are often made by machining processes. For notches in pipes, the depth of which exceeds the thickness of the pipe wall, but also cutting processes are reaching their limits. A generic workpiece or method for producing a non-machined notch is, for example, as the US 2005/016248 A1 known. However, the shaping process takes place without consideration of the shape of the underside of the notch wall.

It is therefore an object of the invention to provide a workpiece with such notches and to provide a method for producing not-machined notches, wherein the underside of the notch wall has a predetermined shape.

The above object is achieved with a workpiece according to claim 1 and a Method according to claim 7.

The workpiece according to the invention has an upper side and a lower side, as well as a non-machined notch. This notch has side faces and one Kerbgrund on; the notch extends from the top to the bottom of the tool and penetrates the entire thickness of the workpiece.

It is thus at least in the region of the notch base, but usually also in the region of the side surfaces of material of the workpiece moved over the bottom of the workpiece addition. The depth of the notch, so the distance from the top of the workpiece, to which the notch attaches to the notch base, can be greater than the thickness of the workpiece itself, ie the distance between the top and bottom of the workpiece. The depth of the notch may be at least 10%, preferably at least 20%, preferably at least 40%, more preferably at least 50% more than the thickness of the workpiece. The depth of the notch exceeding the thickness of the wall piece is referred to as a notch wall, which consequently adjoins the side surfaces and includes the notch base.

According to the invention, the workpiece can be provided with notches whose cross-section is approximately U-shaped with respect to the upper side of the workpiece, ie in which the side surfaces are approximately at a right angle with respect to the upper side of the workpiece. Consequently, these are notches with a substantially flat, preferably flat notch base. The side surfaces of the notch may be located at an angle α greater than 70 °, preferably greater than 80 °, more preferably greater than 85 °, with respect to the top of the workpiece prior to notching. It is thus possible according to the invention to arrange the notch in a workpiece according to the invention with side faces arranged at least in sections approximately at right angles to the upper side. Preferably, the approximately rectangular portions of the side surfaces extend to the top of the workpiece.

Notches of approximately U-shaped cross section are often required in the design of a workpiece when they are part of Verriegelungsanordrungen. It is obvious that the safety aspect plays a special role in locking arrangements, so that the notch geometry must be reliably maintained. Typical use case for such notches is the requirement of pipes of Headrests with deep, U-shaped notches to provide. Latches attached to the car seat engage in these notches so that the tight fit of the headrests is ensured. The above-described notches can be introduced into any type of workpiece, that is also in tubular workpieces.

According to a further preferred embodiment, a workpiece is provided according to the invention, which is provided with a notch whose angle of incidence β is up to 10 °. The angle of incidence β is measured between the top of the workpiece before the notch (horizontal) and the top of the workpiece after notching. Preferably, the incidence angle resulting from the notches is up to 5 °, more preferably up to 3 °, advantageously up to 1 °. A low angle of incidence often has to be met if the side surfaces of the notch are arranged approximately perpendicular to the top of the workpiece. By maintaining a low angle of incidence, the portion of the side surface approximately perpendicular to the top of the workpiece is maximized. The smaller the angle of incidence, the better the notch is suitable as an element of a latching arrangement. It is regarded as a particular advantage of the invention that workpieces have been developed with notches, which have a particularly deep, pronounced U-shaped cross-section, ie have an angle α selected as large as possible and an angle β selected as small as possible.

According to an advantageous embodiment of the invention, the notch wall in the region in which the notch extends beyond the underside of the workpiece, in the region of the notch base, ie on the notch facing side of the notch wall, a different contour than the underside of the notch wall , The notch is created in this case with a tool that is composed of punch and die. The cross section of the notch on the "inside" is determined by the contour of the punch. The punch is molded according to the notch geometry requirements, such as the length and orientation requirements of the side surfaces, the contour of the notch root, or the angle of incidence. The die, on the other hand, is generally not subject to such stringent mold requirements. It can be inventively formed freely depending on the material of the workpiece. It is inventively advantageous if the formed by the die bottom of the notch wall another Contour than the formed by the punch inside of the notch wall.

It is further preferred if the notch wall and possibly also the notch base in the area in which the notch extends beyond the underside of the workpiece has sections of different wall thickness.

It has been found that both the different shapes of the inside and underside of the notch wall and the provision of sections of different wall thickness have a very advantageous effect on the possibilities for the design of the notch. In particular, the previously not by machining non-manufacturable notches with U-shaped cross-section and especially with deep U-shaped cross-section, in which the notch extends from the top to the bottom of the workpiece or beyond, can be reliably prepared by chipless machining be when the notch wall has sections of different contour and wall thickness.

It makes sense for many embodiments, when the wall thickness of the notch wall increases towards the side surfaces. A small wall thickness of the notch wall in the region between the side surfaces or at a distance from the side surfaces can be readily accepted for most embodiments. Especially at the transition from the side surfaces, which are in the range of wall thickness of the workpiece, to the notch wall, which is shifted out of the range of wall thickness of the workpiece, it is advantageous to provide a greater wall thickness to flow of the material of the workpiece in the notch wall to allow in. It is this design that helps to create particularly deep notches.

A tool for embossing a notch has a punch that penetrates into the workpiece and there forms the contour of the notch in the workpiece and a die, which coins the underside of the notch or of the notch base, characterized in that the punch the workpiece against the die suppressed. The die has a land in the area of the notch bottom. In addition, the die has a recess in the region of the transition from the notch root to at least one side face of the notch.

The formation of the die with web and recess is essential for the formation of particular deep U-shaped notches in workpieces. Notches extending across the entire thickness of the workpiece require shifting material of the workpiece beyond the bottom of the workpiece. The greater the angle α between the top and side surface of the notch, the sooner a non-cutting deformation of the workpiece causes a shearing or cutting of the material. It has surprisingly been found that this shearing or cutting can be counteracted very effectively if the recess in the die can accommodate sufficient material of the workpiece, which is displaced by the penetrating Stegpel. This material preferably flows into the recess and is then available for forming the notch base

Nevertheless, in order to ensure a precise shaping of notch root and side surfaces by the Stegpel, it is intended to arrange a web in the die. The web is advantageously located in the middle of the notch base evenly spaced from the side surfaces. The bridge ensures that the notch base can be shaped in a controlled manner by the punch chin.

According to an advantageous embodiment, the die is formed so that the recess in the region of the side surfaces of the notch extends beyond the web. The recess, which is preferably arranged in the transition region between the notch root and side surfaces of the notch, thus extends according to this preferred embodiment not only beyond the depth of the notch or the notch root defined by the web. The die in this case is thus designed in cross-section approximately like a "W", in which the recess extends beyond the upper edge of the web out into the region of the side surfaces of the notch. In particular, where the notch extends beyond the thickness of the workpiece, it creates space in the region of the side surfaces for the flow of the material of the workpiece. Thus, such a template is particularly suitable for producing deep, U-shaped notches.

In this embodiment, if the depth of the recess has at least the thickness of the notch wall, shearing or cutting of the material of the workpiece will occur effectively avoided when forming the notch.

If the recess is provided with a rounded contour, this also helps to support the flow of the material of the workpiece. Above all, a rounding .. in the transition from the side surfaces in the recess and in the transition from the web into the recess into it proven rounded transitions in the contour of the recess.

An advantageous embodiment of the tool provides that the punch and die cooperate in such a way that the notch base is arranged on or under the underside of the workpiece. In this way, particularly deep notches can be marked.

Preferably, punch and die are designed so that they are arranged at a predetermined pressure for introducing the stamp at a predetermined distance from each other and thereby dictate the wall thickness of the notch wall. In this case, the punch and die may have different contours, so that the distance between the punch and die sections is further or less.

In particular, when embossing notches in pipes, a two-part die is preferably used. A two-part die allows easy insertion and removal of the die inside the tube.

• Verformen des Werkstücks durch mindestens ein erstes Werkzeug, dass sich in einer ersten Arbeitsrichtung tangential oder in der Ebene des Werkstücks abschnittsweise in das Werkstück hinein bewegt
• Verformen des Werkstücks durch mindestens ein zweites Werkzeug, dass sich in einer zweiten Arbeitsrichtung tangential oder in der Ebene des Werkstücks abschnittsweise in das Werkstück hinein bewegt, wobei die zweite Arbeitsrichtung der ersten Arbeitsrichtung entgegengesetzt ist.

The invention further includes a method for non-cutting notches in a workpiece. This procedure presupposes the following steps in its basic conception:

• Deforming of the workpiece by at least one first tool that moves in a first direction of work tangentially or in the plane of the workpiece in sections into the workpiece
• Deformation of the workpiece by at least one second tool that in a second direction tangentially or in the plane of the workpiece sections moved into the workpiece, wherein the second working direction of the first working direction is opposite.

It is regarded as a significant advantage of this method that not material is conveyed out of the notch to be created, but on the contrary. In known methods z. B. rolling out notches by a plurality acting in the same direction rollers material from the range to be created notch. The excess material was then slipped off one end of the notch.

When embossing the notch, displaced material of the workpiece was shifted toward the side surfaces.

The inventive advantage of the method according to claim 7 is particularly evident in the notching of pipes. Deep notches and notches of approximately U-shaped cross section are limited or expensive to produce with the previously known methods. This is because, as a rule, not enough material for the notch wall is available for such deep notches in pipes. The notch bottom is a weak point in the notches, which are deeper than the pipe wall. Particularly noticeable is this vulnerability z. B. when crash tests for vehicles, the headrest, which is held in such a notch, breaks off upon impact, because the tube in the notch base or in the notch wall has too little material to withstand the impact.

In the method according to the invention, displaced material is displaced in the direction of the notch base or the notch wall to be created. It is therefore promoted material exactly where it is necessary for reasons of strength and to create notches with extremely large notch depth.

According to a preferred embodiment, the method according to the invention is applied in such a way that the sections in the workpiece which are deformed by the first and the second tool overlap. This achieves as uniform a deformation as possible from the outset. Such an overlap of the paths of the tools is not absolutely necessary because - as will be explained below - also still other possibilities of chipless deformation in the inventive method can be included. However, it proves to be advantageous, in particular if only the one or more first and second tools are used for producing the notch.

Rollers or slides are preferably used according to the invention as tools. Roller tools and slides are known for non-cutting making notches per se. But they are always used in one direction and usually in a sequence of several tools in succession to produce a notch desired contour. In the context of the present invention, it is preferred to use as few tools as possible. Nevertheless, of course, especially if a lot of material is to be deformed or if a complex contour is to be created, different tools can be used, including tools that work in the same direction, but have a different contour. It is to be regarded as advantageous when using rollers that an angle of incidence β of less than 5 °, preferably of less than 3 °, particularly preferably of less than 1 °, can be maintained without problems, because when the tool is being rolled, the material is not drawn into the material Notch into it, as z. B. is typical for embossing.

According to an advantageous embodiment of the method according to the invention deform one or more first and second tools the workpiece in several operations. Preferably, a stationary arranged workpiece is processed. The first and second tools are movable, e.g. B. on rails or mounted on a carriage and move relative to the workpiece. They do not deform the workpiece in one operation but in several steps, for example, first a flat notch is made, which is then deepened in further operations until it has reached its final contour. In this way, notches with complex and / or precise contours can be made and notches can be made in which large amounts of material to be deformed.

According to the method of the invention, the workpiece to be scored is further deformed by stamping after being deformed by the first and second tools to produce the notch. The embossing proves itself as a second processing step, in particular for producing the final notch depth, as advantageous. After the contour between the upper side of the workpiece and side surfaces is created by a tangential or lateral force application of the first and second tools, the radial force application in a third working direction of the embossing stamp causes the molding of the notch base with little effort.

The invention will be explained below with reference to an embodiment.

Fig. 1

eine Querschnittsansicht eines Werkstücks vor einem Kerbvorgang zusammen mit einem Werkzeug, bestehend aus Prägestempel und Matrize,

Fig. 2

die Ausführungsform gemäß Fig. 1 in einem ersten Schritt des Kerbvorgangs,

Fig. 3

die Ausführungsform gemäß Fig. 1 in einem zweiten Schritt des Kerbvorgangs,

Fig. 4

eine Querschnittsansicht eines bearbeiteten Werkstücks nach dem Kerbvorgang und

Fig. 5

einen vergrößerten Ausschnitt der Ansicht aus Fig. 5 sowie

Fig. 6

eine perspektivische Darstellung eines nach dem erfindungsgemäßen Verfahren hergestellten Werkstücks.

In the figures shows

Fig. 1

a cross-sectional view of a workpiece before a notching operation together with a tool consisting of die and die,

Fig. 2

the embodiment according to Fig. 1 in a first step of the notch process,

Fig. 3

the embodiment according to Fig. 1 in a second step of the notch process,

Fig. 4

a cross-sectional view of a machined workpiece after the notching process and

Fig. 5

an enlarged section of the view Fig. 5 such as

Fig. 6

a perspective view of a workpiece produced by the method according to the invention.

Fig. 1 shows a sectional view of the workpiece 1 together with the tool assembly consisting of punch 2 and die 3. To simplify the illustration only a partial section of the workpiece 1 has been shown. Also, the punch 2 is only partially shown at the top, not shown end of the punch 2 is a suitable device for exercising a matched to the material of the workpiece 1 pressure arranged, such as, for example, a pneumatically actuated plunger. The punch 2 and the die 3 are made of hardened steel.

The die 3 has a web 4 in its longitudinal extension, laterally two recesses 5a, 5b are arranged. The web 4 serves as a stop to specify a controlled notch depth for the later notching process.

The recesses 5a, 5b extend in the direction of movement of the punch 2 beyond the web 4 and have a round contour line, so that a cutting action during the notching process is avoided ,

For notching a metallic workpiece 1 having a thickness of 1.5 mm, a force of approximately 60 kN is exerted on the workpiece 1 by punch 2 and die 3. As a result, the punch 2 displaces the material of the workpiece 1 in the direction of the die 2, as in FIG Fig. 2 shown. The material of the workpiece 1 flows through the pressure exerted in the recesses 5a, 5b of the die 3, which are designed so that they can completely absorb the flowing material. The projecting web 4 and the pressing pressure of the punch 1 determine the notch depth. Depending on the pressing pressure of the punch 1, a layer of shifted material of defined thickness, which forms a notch base 6, forms between the punch 1 and the web 4, as in FIG Fig. 3 shown. The two recesses 5a and 5b are now completely filled by displaced material. The design of the recesses 5a, 5b must be chosen so that they are sufficient to receive the displaced material of the workpiece 1. However, depending on the application and the desired geometry of the notch, the recesses 5a, 5b can also be larger.

A notched according to the method described above workpiece shows Fig. 4 , The figure clearly shows that the notch base 6 lies outside the original underside of the workpiece 1. The method allows extremely deep notches with the advantageous use of thin-walled workpieces, such as. Tubes. The shaping the recesses 5a, 5b of the die 3 produced at the notch walls sections of different wall thickness. Particularly in the areas of the transition from the region of the notch base 6 to the side walls, a thicker wall thickness with respect to the mechanical stability of the notch is advantageous. However, the recesses 5a and 5b of the die 3 can be adapted to the desired geometry of the notch.

Fig. 5 shows the definition of the angle of incidence β and the angle a in an enlarged partial view of the surface of the workpiece Fig. 4 , The angle of incidence is measured between the original surface of the workpiece and the notch of the surface of the workpiece at the notch. The angle a is measured between side wall of the notch and original surface.

Fig. 6 shows a perspective view of a notched pipe section 7. The pipe section 7 has a wall thickness W. The notch is made by a per se known rolling tool in a first working direction A tangential to the pipe section 7 to the apex of the pipe section, but not over the entire Length of the notch was guided. Subsequently, a second rolling tool in a second working direction B opposite to the working direction A, so also tangent to the pipe section 7 to over the vertex of the pipe section, but not over the entire length of the notch out. The rolling tools known per se are not shown here for reasons of clarity.

The first and second rolling tools are alternately guided five times in the pipe section. The notch depth is then the same depth as the wall thickness. The material from the pipe wall has been largely shifted to the notch bottom. The embossing die (not shown), which now radially deforms from the third working direction C, increases the notch depth T to the full extent, which is more than 50% above the wall thickness W. By using the method according to the invention, far more material is available for producing the notch wall than in known methods. Accordingly, the notch thus produced has, among other things, a higher strength than notches produced by known methods.

Claims (8)

1. Work piece with an upper side and with a lower side and with a non-cutting produced notch which has side faces and a notch root (6), whereby the notch extends at least from the upper side to the lower side of the work piece (1), characterized in that the notch has in the area which extends beyond the lower side of the work piece (1) a notch wall for which the contour of the notch root (6) and the lower side of the notch wall formed by a matrix (3) are configured differently.
2. Work piece according to claim 1, characterized in that the depth of the notch is at least 10% deeper, preferably at least 20%, preferably at least 40%, particularly preferably at least 50% deeper than the thickness of the work piece (1).
3. Work piece according to claim 1 or 2, characterized in that at least one side face of the notch is placed with respect to the upper side of the work piece (1) at an angle a of more than 70°, preferably of more than 80°, particularly preferably of more than 85°.
4. Work piece according to at least one of the preceding claims, characterized in that the angle of incidence β is up to 10°, preferably up to 5°, particularly preferably up to 3°, advantageously up to 1°.
5. Work piece according to at least one of the preceding claims, characterized in that the notch wall has portions of different wall thickness.
6. Work piece according to at least one of the preceding claims, characterized in that the wall thickness of the notch wall increases from the notch root (6) to the side faces.
7. Method for producing a notch in a work piece (1) made of metal with the steps:

   - deformation of the work piece (1) by at least one first tool which moves in a first working direction tangentially to or in the surface plane of the work piece (1) sectionwise into the work piece (1)

   - deformation of the work piece (1) by at least one second tool which moves in a second working direction tangentially to or in the surface plane of the work piece (1) sectionwise into the work piece (1), whereby the second working direction is opposed to the first working direction,

   characterized in that, after the deformation of the work piece (1) by the first and by the second tool, the work piece (1) is further deformed by stamping between a stamping punch (2) and a matrix (3) cooperating with the stamping punch (2) in order to produce the notch.
8. Method according to claim 7, characterized in that as a first and/or as a second tool a slider or a roller deforms the metal.

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