EP1704935A1 - Circular part - Google Patents

Abstract

The circular part has a radial section having three parts with different wall thickness. The parts are made by a material-deforming tool such as a pressing tool. The parts in relation to the output wall thickness (t) are variable and adapted to mechanical loads of the circular part.

Description

The invention relates to a rotationally symmetrical component of a disk-shaped preform, which has at least three peripheral regions with different wall thicknesses over its radial extension, wherein the peripheral regions of the disk-shaped preform are produced by a forming tool, preferably at least one spinning roller.

For producing rotationally symmetrical components, it is known to use as the starting material a disc-shaped preform, for example a sheet metal blank or a forging blank, from which, in subsequent processing steps, e.g. Flywheels, pulleys or other transmission components are manufactured. Instead of a disk-shaped preform, it is also possible to use another preform which, however, then has at least one disk-shaped region.

Out DE 101 60 038 C1 is a generic rotationally symmetric component known. This component is produced from a rotationally symmetrical preform with a disk-shaped hub region, wherein the disk-shaped hub region of the rotating relative to at least one axially and radially movable pressure roller rotating preform by pressing means of at least one spinning roller at least in a radial central region in its wall thickness and thereby displaced material to increase the outer diameter of the preform is displaced radially outward without increasing the wall thickness. This method offers the possibility of dimensioning the initial wall thickness of the preform with a disc-shaped hub region so large that the radially inner connection region has sufficient strength, eg for connection to the crankshaft of a motor vehicle, and the radially outer edge region of the circular sheet metal continues by a simple process can be thickened, for example, at To enable toothing rings the formation of the teeth. Since the hub region would be too stiff with such a large output wall thickness, the radially middle section of the sheet metal blank or preform is so far diluted by the pressing process that it satisfies the requirements of the axial flexibility of the component. In this case, the material which is obtained by the wall thickness reduction, used to increase the diameter of the component, ie there are only radial peripheral regions with respect to the initial wall thickness of the preform reduced wall thickness.

Out DE 44 44 526 C1 It is known to deform from the radial surface of a sheet metal sheet metal sheet by means of a pressure roller radially inwardly to the formation of a radially inwardly disposed hub. In this case, the output wall thickness of the sheet metal blank decreases at the radial peripheral portion and it is formed an axially extending inner hub. It is thus possible to form a component with an inner hub from an initially flat sheet metal blanks. However, this component has a uniform wall thickness over its actual radial peripheral area.

The object of the invention is to improve a generic component so that it can be adapted by non-cutting forming in a simple manner to different mechanical requirements.

This object is achieved in a rotationally symmetrical component of the type described above according to the invention that it has peripheral regions with respect to the initial wall thickness of the preform larger and smaller wall thickness, wherein the wall thicknesses of the peripheral regions are adapted to the mechanical component stresses in the respective peripheral regions.

It is thus possible by non-cutting forming, preferably by spin forming, from a disc-shaped preform (eg sheet metal blank or forging blank) to create a component which is formed in various radial peripheral regions by changing the Ausgangswanddicke so that it meets the respective different mechanical requirements in these areas. Thus, for example, the flange or hub region can be thickened relative to the starting wall thickness and the radially adjacent region can be deliberately reduced in wall thickness, while the radially outer region is thickened again in order to increase the flexibility of the component in certain areas, for example in flywheels, in others In contrast, the wall thickness should be set as large as required by the mechanical stresses of the component in later use.

According to a first preferred embodiment, it is provided that all peripheral regions have a wall thickness deviating from the starting wall thickness, i. All peripheral areas are then reduced or increased in relation to the preform in their wall thickness.

Alternatively, it may also be provided that at least one peripheral region has the initial wall thickness, i. this area is not changed in the wall thickness.

A particularly preferred further embodiment is characterized in that at least one circumferential region is provided, which extends in relation to another circumferential region in both axial directions. It is thus possible to form the respective thickened peripheral region not only in an axial direction thickened, but in both directions, which can be realized, for example, by spin forming with a correspondingly shaped receptacle for the preform or by the fact that the component after a first flow-forming taken from the recording and subsequently processed by the axially other side by spin forming becomes.

The invention also proposes a method for producing a previously described rotationally symmetrical component from a rotationally symmetrical preform, which is characterized in that at least one peripheral region of the relative to at least one movable in the axial and radial direction forming tool, preferably a spinning roller, rotating preform by pressing means of reduces at least one spinning roller in its wall thickness and the thereby displaced material is displaced in a radially adjacent peripheral region with wall thickness increase.

In this way it is possible, by means of at least one radially and axially adjustable pressure roller to reshape the rotationally symmetrical preform so that peripheral regions are created with the desired wall thickness by the material of the preform is displaced radially corresponding.

In a preferred embodiment, it is provided that material is displaced from the at least one spinning roller into the outer peripheral region of the preform. This method is preferably provided when a component is to be created, which should have a greater wall thickness radially outside, for example, to introduce a toothing, and which adjacent to this area should have a smaller wall thickness, for example, a required for the component Flexibility to adjust, eg if the component is to form a one-piece starter ring gear.

In this case, it is further advantageously provided that the thickened outer peripheral region is then axially thickened by means of a further, at least radially deliverable from the outside forming tool. This additional thickening step is then provided when the required axial thickening so it is great that they can not be reached by moving material radially from the inside to the outside.

Fig. 1

eine scheibenförmige Vorform,

Fig. 2 bis 6

unterschiedliche Ausführungsformen eines rotations-symmetrischen Bauteils mit Umfangsbereichen mit unterschiedlichen Wanddicken,

Fig. 7

ein weiteres rotationssymmetrisches Bauteil während des Umformformvorganges,

Fig. 8

das Bauteil nach Fig. 7 vor einem Nachbearbeitungs-wandverdickungsschritt und

Fig. 9 und 10

mögliche Außenquerschnittsformen des Bauteils nach Fig. 8.

The invention is explained in more detail below by way of example with reference to the drawing. This shows on average in:

Fig. 1

a disc-shaped preform,

Fig. 2 to 6

different embodiments of a rotationally symmetrical component with peripheral regions with different wall thicknesses,

Fig. 7

another rotationally symmetrical component during the forming process,

Fig. 8

the component of FIG. 7 before a post-processing wall thickening step and

FIGS. 9 and 10

possible outer cross-sectional shapes of the component according to FIG. 8.

FIG. 1 shows the starting product for a rotationally symmetrical component according to the invention, namely a disc-shaped preform 1, which is e.g. is formed by a sheet metal blank or a forging blank. This preform 1 has a uniform initial wall thickness t.

According to the invention, it is now provided that a rotationally symmetrical component is formed from such a disk-shaped preform 1 by deformation, preferably by spin forming, wherein this component has peripheral regions with a larger and smaller wall thickness than the initial wall thickness t of the preform 1.

FIGS. 2 to 6 show various embodiments of such a component.

FIG. 2 shows a rotationally symmetrical component 2 which has radially on the inside a first circumferential region U _{1 which} has a greater wall thickness t ₄ than the initial wall thickness t. Radially on the outside, a peripheral region U ₂ adjoins this peripheral region U ₁ , this peripheral region U ₂ has a wall thickness t _{3 which is} significantly reduced in relation to the initial wall thickness t. Radially outside on the peripheral region U ₂ is followed by a peripheral region U ₃ , this has a relative to the output wall thickness t increased wall thickness t. ₁ In this case, the forming is carried out starting from the preform 1 such that the inner peripheral region U ₁ extends in both axial directions relative to the adjacent peripheral region U ₂ , whereas the peripheral region U ₃ extends only in an axial direction relative to the peripheral region U ₂ (in FIG Sense of Figure 2 above).

The deformation of the preform 1 to the component 2 is preferably carried out by means of at least one spinning roller, which presses the preform 1 by spin forming in a correspondingly shaped recording or counter-mold, if necessary, this can be done in several steps with multiple recordings or counter-forms.

FIG. 3 shows a component 2 which in principle corresponds to the component according to FIG. 2, again there are three different peripheral regions U ₁ , U ₂ , U ₃ , wherein the wall thickness t _{7 of} the radially inner peripheral region U _{1 is} greater than the initial wall thickness t , the wall thickness t _{6 of} the central peripheral area U _{2 is} smaller than the initial wall thickness t and the wall thickness t _{5 of} the outer peripheral area is greater than the initial wall thickness t.

In contrast to the embodiment of Figure 2 is the Wall thickness t _{5 of} the outer peripheral portion U ₃ greater than the wall thickness t _{7 of} the inner peripheral portion t ₇ , also extends the peripheral region U _{3 seen} in the axial direction on either side of the central peripheral region U ₂ as well as the inner peripheral portion U _first

In the embodiment according to FIG. 4, three circumferential regions with different wall thickness are again provided. In this embodiment, the inner peripheral region U _1, the largest wall thickness, namely t ₉ , this is greater than the initial wall thickness t. This is followed by the middle peripheral region U ₂ with a reduced wall thickness t ₈ , while the outer peripheral region 3 has not undergone a change in wall thickness, ie the wall thickness of the outer peripheral region U ₃ corresponds to the initial wall thickness t. The thickened inner peripheral region U ₁ extends, viewed in the axial direction, with respect to the adjacent peripheral region U ₂ only in one direction.

FIG. 5 shows a further embodiment which has essentially four peripheral regions with different wall thickness. The radially inner peripheral portion U ₁ has a relation to the output wall thickness t reduced wall thickness t ₁₀ , to this area, a peripheral region U ₂ connects with respect to the output wall thickness t increased wall thickness t ₁₁ . This peripheral region U ₂ merges into a peripheral region U ₃ with a wall thickness t ₂ which is smaller than the initial wall thickness t. Radially outside adjoins the peripheral region U ₃ a peripheral region U ₄ , the wall thickness has not changed, ie the output wall thickness t corresponds. As can be seen, the peripheral region U ₂ extends axially in both directions relative to the circumferential regions U ₁ and U ₃ , while the peripheral region U ₄ extends only in an axial direction relative to the peripheral region U ₃ (upward in the sense of FIG. 5).

Another embodiment is shown in FIG. This component has four peripheral regions, the inner peripheral region U ₁ has a wall thickness t ₁₃ , which is significantly greater than the initial wall thickness t. This is adjoined by a peripheral region U ₂ having a wall thickness t ₁₂ which is significantly smaller than the initial wall thickness t. The region U ₂ passes radially outward into a peripheral region U ₃ which has the same wall thickness as the peripheral region U ₁ , namely t ₁₃ . Radially on the outside, the peripheral region U ₃ merges into a peripheral region U ₄ whose wall thickness corresponds to the output wall thickness t. In this embodiment, the peripheral regions U ₁ and U ₂ with a greater wall thickness than the adjacent peripheral regions U ₂ , U _{4 seen} in the axial direction extends only in one direction (upward in the sense of Figure 6).

FIG. 7 shows a further component 3, which is received in a workpiece holder 4 with an outer radial stop 5. In this case, material has been displaced radially outward by means of a pressure roller 6, adjacent to a radial inner peripheral region U ₁ with the outlet wall thickness t, so that already a peripheral region U ₂ with reduced wall thickness t ₁₅ and a radial outer peripheral region U ₃ with greater wall thickness t ₁₄ was formed, at the same time the diameter of the preform has been increased. The component 3 according to FIG. 7 thus has radially on the inside a circumferential region with the output wall thickness, adjacent thereto a peripheral region U ₂ with a smaller wall thickness t ₁₅ and radially outside a peripheral region U ₃ with increased wall thickness t ₁₄ .

If this component 3 is to be further axially thickened in the radially outer peripheral region U ₃ , it is clamped in accordance with FIG. 8 into a workpiece holder 7, which receives the peripheral regions U ₁ and U ₂ and out of which the already thickened peripheral region U ₃ protrudes freely outward. This peripheral area U ₃ can then be further axially thickened, for example, with a radially deliverable spinning roller 8, so that an axially thickened peripheral edge region is formed, which may have, for example, a profile according to FIG. 9 or FIG. In such an axially thickened peripheral edge region, for example, teeth of a toothing can subsequently be formed, preferably by machining. Such a component can then form, for example, a one-piece starter ring gear.

In principle, a variety of other design options are known, the above embodiments are only examples. Instead of the disc-shaped preform 1 of Figure 1, in principle, another preform can be used, but then has at least one disc-shaped region, the wall thickness subsequently changed differently in different peripheral regions becomes.

Claims (7)

A rotationally symmetrical component comprising a disc-shaped preform, which has at least three circumferential regions with different wall thicknesses over its radial extension, the peripheral regions being produced from the disk-shaped preform by a forming tool, preferably at least one spinning roller.
characterized,
that there are circumferential regions with greater (t ₁ , t ₄ , t ₅ , t ₇ , t ₉ , t ₁₁ , t ₁₃ , t ₁₄ ) than the initial wall thickness (t) of the preform and smaller ones (t ₃ , t ₆ , t ₈ , t ₁₀ , t ₁₂ , t ₁₅ ) wall thickness, wherein the wall thicknesses of the peripheral regions are adapted to the mechanical stresses of the component in the respective peripheral regions. Component according to claim 1,
characterized,
in that all peripheral regions have a wall thickness deviating from the initial wall thickness (t). Component according to claim 1,
characterized,
in that at least one circumferential region has the initial wall thickness (t). Component according to one or more of claims 1 to 3,
characterized,
in that at least one circumferential region is provided, which extends in relation to another circumferential region in both axial directions. Method for producing a rotationally symmetrical component according to one or more of Claims 1 to 4 from a rotationally symmetrical preform,
characterized,
that at least one peripheral region of the relative to at least one movable in the axial and radial direction forming tool, preferably a spinning roller rotating preform by pressing means of the at least one spinning roller in its wall thickness and displaced thereby displaced material in a radially adjacent peripheral region with wall thickness increase. Method according to claim 5,
characterized,
that material is transferred from the at least one spinning roller into the outer peripheral region of the preform. Method according to claim 6,
characterized,
that the thickened outer peripheral region is then axially thickened by means of a further at least radially deliverable from the outside forming tool.

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