The invention relates to a component, in particular a metal sheet, having a press-in element, in particular a press-in nut, pressed into a hole of the sheet. The invention also relates to such a press-in element and to a method of pressing the press-in element into the component.
A press-in nut serves for forming a screw fastening means on a thin-walled component, such as a metal sheet for example. To this end, it is pressed into the sheet and held therein in a form-fitting manner. It normally has an internal thread, into which a screw can be screwed. As an alternative to the configuration as a press-in nut, “press-in studs” are also know as press-in elements, which differ from the press-in nut essentially by a stud provided, for example, with an external thread and integrally formed in a fixed manner. The press-in element normally has a head part with a web integrally formed on its underside. The web may also be designated as flange or collar. When being pressed in, the press-in element is inserted with the web into a hole of the component and, with the head part, bears like a shoulder on the hole margin. Provided as anti-rotation protection is, for example, a web of non-circular design and having edges. Radially integrally formed ribs may also be formed as anti-rotation protection on the underside of the head part, these ribs being pressed into the sheet during the setting.
Different methods are known in order to form the form-fitting connection during the setting operation, in order thus to secure the press-in element against falling out.
Thus, for example, the procedure is often for the web height of the press-in nut to exceed the component thickness and for the projecting portion of the web to be bent over, so that the component is clamped in place between the head part of the press-in nut and the bent-over section of the web. However, such press-in nuts with a bent-over margin only lead to unsatisfactory results in the case of thick sheets. The expression “thick sheets” in this case refers to sheets having a sheet thickness greater than 2.5 mm and in particular also greater than 3.5 mm.
WO 82/02579 discloses a press-in nut in which a web is incorporated in an annular groove below the head part. During the press-in operation, material of the sheet is pressed into this groove by cold working as a result of a corresponding configuration of the underside of the head part. DE 29 20 211 A1 discloses a similar principle, the web here being designed like a dovetail and forming an undercut with the head part, into which undercut material is again pressed by shaping of the sheet during the setting operation.
DE 28 18 756 A1 discloses a press-in or threaded nut in which the web or flange adjoining the underside of the head part has a height corresponding to the component thickness. The flange forms an obtuse cone angle by upsetting during the setting operation, as a result of which, on the one hand, the flange forms an undercut with the head part and, on the other hand, sheet material is enclosed in this undercut.
The object of the present invention is to ensure simple and reliable fastening of a press-in element, in particular a press-in nut, also in thick components.
This object is achieved according to the invention by a component having the features as claimed in claim 1.
The component has a press-in element, in particular a press-in nut, pressed into a hole and having a head part and an adjoining web. Now it is essential that the height of the web is less than and thus independent of the component thickness, and that a deformation region of the web is provided. This deformation region is shaped and pressed into the hole wall during the setting operation.
This configuration has the decisive advantage that, to form a form-fitting connection between the press-in nut and the component, it is not the component that is deformed but only the web, which is pressed into or cuts into the component. In the press-in region, only a displacement of the component material takes place. In the set final state, the pressed-in deformation region is completely surrounded by the material of the component due to the pressing into the hole wall. As a result, the press-in nut is held in an especially reliable and lasting manner. A form fit acting in two axial directions is formed between the web and the component material. The complete enclosure of the deformation region rules out the possibility of the bent-over deformation region giving way again slightly, as a result of which the reliable seating would be impaired.
A further substantial advantage can be seen in the fact that such a press-in nut is largely independent of the component thickness, since the extent to which the component thickness exceeds the height of the web is of no importance for the firm seating. The press-in nut can therefore be used universally for widely differing component thicknesses, and different press-in nuts need not be produced and kept in stock for different thicknesses.
Furthermore, such a press-in nut is simple to realize from the production point of view, since no special measures for forming an undercut, for example, have to be taken during the production. The processing, that is to say the pressing of the press-in nut into the component, can also be carried out without any problems and in a simple manner on account of merely a single-stage setting operation.
According to an expedient development, the web has a shank region which extends into the hole and preferably runs parallel to the hole wall and adjoining which is the deformation region. In this case, the outside diameter of the shank region corresponds in particular to the inside diameter of the hole. As a result, the shank region, even in the set state, forms a type of sleeve and thereby provides especially good seating of the press-in nut in the hole. The sleeve formed by the shank region also provides for especially good guidance of a screw which is screwed, for example, into the press-in nut. Due to the configuration with the undeformed shank region and the shaped deformation region, the web is therefore shaped only in one section.
In this case, the shank region expediently has an internal thread having in particular a plurality of thread turns. By means of this measure, a comparatively elongated thread region and thus a reliable hold of a screw are achieved.
With regard to a simple setting operation, the deformation region, on the inside at the end, has a bevel designed in particular like a conical taper. During the setting, this bevel interacts with a die head of a die, the die head preferably being designed to be complementary to the bevel of the deformation region.
The object is also achieved according to the invention by a press-in element having the features of patent claim 5, this press-in element having a head part and an adjoining web with a shank region and an adjoining deformation region, only the deformation region being provided for the radial widening.
Preferred configurations of the press-in element can be gathered from the subclaims. The advantages cited with regard to the component with pressed-in press-in element and preferred configurations can accordingly be applied to the press-in element.
According to a preferred configuration, provision is made in particular in this case for the outer wall of the web, in the unfitted state, to be oriented perpendicularly or with an obtuse angle being enclosed with the underside of the head part. With regard to the wall of the hole, the web, in the state in which it is not set, therefore runs parallel to the hole wall or, for forming an insertion bevel, slightly inclined relative to the hole wall. No undercut is formed between the web and the underside of the head part. The outside diameter of the web, or the largest outside diameter in the case of the inclined configuration, preferably corresponds to the inside diameter of the hole, except for a necessary tolerance margin. The press-in element has a sleeve-like web which is simple to produce and has a shank region and a deformation region with smooth outer wall and without grooves or the like.
Furthermore, according to an expedient configuration, a locking web is provided which is arranged on the underside of the head part at a radial distance from the web. The locking web is likewise preferably of annular design and is arranged in particular as a marginal web on the outer margin of the head part. Due to the arrangement of the locking web, the set press-in element withstands higher press-out forces. This is because, when a force acts in the opposite direction to the setting direction, the press-in element is braced in the component by the interaction between the web, molded into the hole wall after the setting operation, and the locking web pressed into the component surface.
At least one recess, preferably a plurality of recesses are preferably arranged on the bottom front end of the web. Since the front end projects into the material in the set state, this configuration results in a form fit which acts in the peripheral direction and forms an anti-rotation locking means for the press-in element pressed into the hole.
The deformation region, at least in the transition region to the shank region, has a reduced wall thickness in comparison with the shank region. As a result, the deformation region can be bent over in a defined manner in the transition region to the shank region. The reduced wall thickness may also be formed by a notch, which defines a predetermined bending point.
The object is also achieved according to the invention by a method of pressing a press-in element into a component. In this case, the procedure is such that the press-in element is inserted with its web into a hole of the component, the component having a component thickness exceeding the height of the web. A die with a tapering die head is inserted from the underside of the component. When the press-in nut is being pressed in, the web is deformed outward in its deformation region on account of the tapering die head and is thereby pressed into the hole wall of the component, to be precise in such a way that the pressed-in section of the web is completely surrounded by the material of the component. In this case, the pressing into the hole wall is ensured in particular by the die head, which projects into the hole and is designed in particular like a cylinder.
For an especially cost-effective and simple setting operation, the press-in element is preferably pressed into the component in a single-stage setting operation. Here, the expression “single-stage” refers to the fact that the insertion of the press-in element into the hole and also the fastening in the hole, in particular the spreading of the deformation region into the hole wall, take place within a working cycle. In particular, the fastening is effected at the same time as the insertion; i.e., during the insertion into the hole, the deformation region is spread out at the same time and thus the press-in element is fastened. At the end of the insertion operation, the fastening has also been completed.
In order to achieve the desired widening of the web, the die preferably has a conical or frustoconical or rounded die head. Due to this configuration, the web, during the setting operation, in which the press-in nut is increasingly displaced against the die, is gradually deformed and pressed into the hole wall. In this case, it is especially advantageous if the die head has an outer surface adapted to the bevel of the web. In particular, the die therefore has a conical taper complementary to the bevel of the web, i.e. the cone angle of the beveled deformation region and that of the die head correspond to one another.
In order to widen the web in the deformation region to the greatest possible extent, the die, in an expedient configuration, has a shank with an outside diameter which is adapted to the hole radius and with which it projects into the hole during the press-in operation. Therefore, except for a necessary tolerance margin, the shank sits in the hole in an accurately fitting manner, so that the die is guided by the hole.
In order to ensure that only a section of the web is deformed and that an internal thread arranged on the inside in the shank region of the web remains undamaged, the die is preferably inserted only partly into the hole during the setting operation.
Exemplary embodiments of the invention are explained below with reference to the figures. In the drawing, in each case in schematic and greatly simplified illustrations:
The press-in nut 2 has a head part 8, adjoining which is a web 10. The head part 8 and web 10 are therefore formed roughly like an L. Furthermore, a plurality of radially running ribs 12 are provided on the underside of the head part 8 in such a way as to be distributed over the periphery, these ribs 12 acting as anti-rotation protection in the set state. The web 10 comprises a shank region 14, which adjoins the head part 8 and adjoining which in turn is a deformation region 16. According to the variant according to
In the region of its head, the press-in nut 2 has a larger outside diameter than the hole diameter, so that the head part 8 overlaps the hole 4, and the press-in nut 2, with the head part 8, comes to bear on the top side of the component 6.
A die 22 is provided for the press-in operation, a cylindrical shank 23 of this die 22 being inserted into the hole 4 from below in at least approximately accurately fitting manner. At its front end adjoining the shank 23, the die 22 has a die head 24, which tapers conically like a frustum of a cone. In this case, the frustum angle is selected in such a way that the outer surface of the die head 24 runs approximately parallel to the bevel 19 of the deformation region 16.
In the exemplary embodiment in
To press the press-in nut 2 into the component 6, the press-in nut 2 is inserted with its web 10 into the hole 4 and sits there at first largely free of play. A press-in force is then exerted on the head part 8 in the arrow direction by a setting tool (not shown here). At the same time, the die 22 is inserted into the hole 4 from below. At the start of the setting operation, the bevel 19 and the outer surfaces of the die head 24 bear approximately flush against one another. The press-in nut is increasingly pressed against the die 22 in the arrow direction. As a result, the deformation region 16 is bent outward into the hole wall 20, so that the deformation region 16 cuts into the material of the component 6. In the process, the press-in nut 2 is pressed in until the underside of its head part 8 bears flush against the surface of the component 6. In this final state, the ribs 12 are molded into the component 6. As can be seen from
In the set final state, as can be seen from
In the configuration according to
An embodiment having a locking web 28 running around the margin on underside of the head part 8 is shown in
According to the embodiment variants in
With press-in nuts 2 described here, with their various embodiment variants, especially reliable fastening of the press-in nut 2 in the hole 4 of the component 6 is made possible by a simple single-stage setting operation. No shaping of the component 6 is required for this purpose. On the contrary, a form fit is formed by virtue of the fact that part of the press-in nut 2, namely part of the deformation region 16, is pressed into or cuts into the hole wall 20 and merely displaces material of the component 6 there. Such a press-in nut 2 is especially suitable for use in thick sheets, since, apart from the reliable fastening, it can be used universally for components having different component thicknesses.