EP3560623A1 - Method and device for producing a final product from an intermediate product by means of mechanical forming - Google Patents

Abstract

A process for producing a final product (1) from an intermediate (2) by means of transformation comprises the following process steps:
Producing the intermediate product (2) which has at least one preform (2a) of at least one projection (1a) to be formed on the end product (1),
- Forming of the intermediate product (2) to the said at least one projection (1 a) end product (1) by means of a forming tool (3) having at least one mold cavity (3a) for producing the at least one projection (1 a).

The intermediate product (2) is positioned in relation to the forming tool (3) during the conversion to the end product (1) such that the preform (2a) is offset from the mold cavity (3a) in such a way that during the deformation of the preform (2a) the protrusion (1a) the material forming the projection (1a) flows at least partially laterally into the mold cavity (3a).

Description

The invention relates to a method for producing an end product from an intermediate product by means of reshaping according to the type defined in greater detail in the preamble of claim 1. Furthermore, the invention relates to a device for carrying out the method.

From the general state of the art, generic methods and devices used therefor are known. The devices are usually follow-on tools with which a final product is produced from a blank in several forming steps. In this way, too high a degree of deformation in the individual forming steps is avoided.

Gears can be produced using a wide variety of manufacturing processes. Among other things, it is known to use this cold forming process. Such cold forming used in the production of gears often leads to insufficient filling of the mold cavity, so that the desired dimensional stability of the components can not be achieved. If sufficient mold filling is achieved, very high pressing forces are required for this, which in turn leads to a very high surface pressure and thus to a considerable tool stress.

Alternatively, such components can also be made by hot working, which may allow for higher mold fillings, but is relatively expensive, since the press tool must be equipped with a device for component heating, which is associated with high costs and also complicates flexible use of the tool. Mostly caused by the heat input In addition, a delay, whereby the dimensional accuracy of the components produced deteriorates. Therefore, the gear is usually additionally calibrated cold at the end of processing.

For the reasons mentioned above, a metal-cutting process is usually used in practice after forming in order to be able to produce such teeth with a sufficient dimensional and dimensional accuracy. However, the additional machining or the cold calibration is associated with sometimes considerable costs and complicates the manufacture of the components.

Small contours or elevations or depressions are often also produced by means of a conventional embossing process.

The DE 197 50 184 A1 describes a method for the production of internal gears in rotationally symmetrical molds by plastic cold forming and a forming tool for performing this method. The toothing is thereby gradually transformed to reduce the pressing force in the individual forming steps. However, the process is quite complex and therefore expensive.

From the DE 10 2005 018 127 A1 the production of a spur toothing on a coupling element is known. This serves to transmit torques about an axis of rotation, wherein the spur gear engages axially in a corresponding counter-toothing. The spur toothing has teeth made of non-cutting plastically shaped material.

DE 10 2005 019 731 A1 describes a hub of a wheel bearing unit with an inner ring seated on the hub. The hub has a collar with a toothing, which is proportionately formed from the material of the inner ring.

A method for producing radial spur gears in workpieces for ball joints for constant velocity joints is from the DE 10 2005 054 023 B3 known. In this case, a bearing surface and an end face are machined and the workpiece is received on one of the machined surfaces and the radial spur toothing is formed.

In the DE 10 2016 002 542 B3 a method for producing internally toothed sliding sleeves is described, in which the tooth profiles of the internal teeth of the sliding sleeve semi-finished products are produced by means of a cold forming process.

The DE 102 13 509 A1 relates to a method for producing an annular part with an internal toothing.

From the EP 2 551 033 B1 For example, a method for forming a front toothing on an inner ring of a wheel hub by means of plastic deformation is known.

However, even with the methods described in said documents, it is not possible to produce teeth or general projections by cold forming in an economical manner and with a sufficient dimensional stability of the components.

It is therefore an object of the present invention to produce a method and an apparatus for producing an at least one projection end product from an intermediate product by forming, which can be operated economically and ensures a high dimensional and dimensional accuracy of the components, in particular the molded-on projections.

According to the invention, this object is achieved by the features mentioned in claim 1.

The inventive method is based on a targeted pre-distribution of the material of the intermediate product and a corresponding positioning of the intermediate product relative to the forming tool, so that in the subsequent Forming in which the end product is formed from the intermediate product, an at least partially lateral flow of the projection of the final product-forming material, ie the intermediate product forming the preform material, is ensured in the mold cavity. In particular, this results in a homogeneous flow of the material into the mold cavity in the lateral direction, ie in a direction deviating from the direction in which the pressing force is applied.

It has surprisingly been found for the inventors that such a lateral flow of the material into the mold cavity leads to a much better filling of the mold cavity with the material forming the projection, which is why the method according to the invention enables an equally accurate and economical production of the final product.

The inventive method also allows a reduction in the force necessary for the forming press force, whereby the forming tool is charged much less and thus certain components can be made only purely by forming technology.

Among other things, the method according to the invention also offers great advantages in the production of smaller contours or elevations or depressions, since especially filigree contours can be reliably produced.

In a very advantageous development of the invention it can be provided that the intermediate product is positioned relative to the forming tool, that when forming the intermediate product to the end product, the preform first comes into contact with a surface of the forming tool that does not belong to the mold cavity. Thereby, the inventive at least partially lateral flow of the material is ensured in the mold cavity in a very reliable manner, since due to the low initial contact surfaces between tool-active surface and workpiece preform already very low forces leads to the voltages required for the flow of the material.

Another very advantageous embodiment of the invention may consist in that the intermediate product is positioned relative to the forming tool, that the preform is at least approximately completely adjacent and immediately adjacent to the mold cavity. This arrangement of the preform of the intermediate with respect to the mold cavity is one way of ensuring the desired lateral flow into the mold cavity upon subsequent forming of the intermediate product into the final product.

A very economical method results when, in a further advantageous embodiment of the invention, the intermediate product is produced by means of forming from a blank.

A further improvement of the economy of the method according to the invention is obtained when the forming of the final product from the intermediate product in a forming of the intermediate from the blank immediately following forming step is performed, as in this way the individual process steps with one and the same system, for example in a Subsequent tool, can be performed. Such an approach also enables the production of very high strength components.

The method according to the invention can be used particularly advantageously if the at least one projection has a tooth form and is part of a tooth system. Especially in the production of gears it has been extremely difficult to produce dimensionally accurate components by means of suitable forming processes, which is why the invention can be used particularly advantageously in this field.

A further advantageous embodiment of the invention may consist in that the at least one preform has a shape corresponding to two teeth, wherein two teeth of the toothing are formed from each preform. This represents a possibility for rationalizing the process and is therefore particularly well suited for mass production.

The method can be used particularly advantageously if the toothing is spur toothing. Namely, the method according to the invention makes possible the first-time forming production of very high, pointed and precisely formed serrations. However, with the method according to the invention, it is also possible to produce conventional toothings arranged on the circumference of a circular body.

When the forming of the intermediate product into the final product is carried out by means of cold forming, a very high surface quality is achieved, as a result of which a subsequent machining operation can be completely eliminated. This significantly increases the cost-effectiveness of the process according to the invention.

In claim 10, an apparatus for performing the method is given. Said device can be used without problems for carrying out the method according to the invention and can be constructed very simply.

Embodiments of the invention are shown in principle with reference to the drawings.

Fig. 1

einen ersten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer ersten Ausführungsform;

Fig. 2

einen zweiten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer ersten Ausführungsform;

Fig. 3

einen dritten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer ersten Ausführungsform;

Fig. 4

einen vierten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer ersten Ausführungsform;

Fig. 5

einen fünften Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer ersten Ausführungsform;

Fig. 6

einen sechsten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer ersten Ausführungsform;

Fig. 7

einen ersten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer zweiten Ausführungsform;

Fig. 8

einen zweiten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer zweiten Ausführungsform;

Fig. 9

einen dritten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer zweiten Ausführungsform;

Fig. 10

einen vierten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer zweiten Ausführungsform;

Fig. 11

einen fünften Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer zweiten Ausführungsform;

Fig. 12

einen sechsten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens in einer zweiten Ausführungsform;

Fig. 13

ein mit dem Verfahren gemäß der Figuren 7 bis 12 hergestelltes Endprodukt;

Fig. 14

ein bei dem Verfahren gemäß der Figuren 7 bis 12 eingesetztes Zwischenprodukt;

Fig. 15

einen ersten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Zwischenprodukts in einer dritten Ausführungsform;

Fig. 16

einen zweiten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Zwischenprodukts in einer dritten Ausführungsform;

Fig. 17

einen dritten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Zwischenprodukts in einer dritten Ausführungsform;

Fig. 18

einen vierten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Zwischenprodukts in einer dritten Ausführungsform;

Fig. 19

einen fünften Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Zwischenprodukts in einer dritten Ausführungsform;

Fig. 20

einen sechsten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Zwischenprodukts in einer dritten Ausführungsform;

Fig. 21

einen ersten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Endprodukts in einer dritten Ausführungsform;

Fig. 22

einen zweiten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Endprodukts in einer dritten Ausführungsform;

Fig. 23

einen dritten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Endprodukts in einer dritten Ausführungsform;

Fig. 24

einen vierten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Endprodukts in einer dritten Ausführungsform;

Fig. 25

einen fünften Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Endprodukts in einer dritten Ausführungsform; und

Fig. 26

einen sechsten Zustand bei der Durchführung des erfindungsgemäßen Verfahrens zur Erstellung des Endprodukts in einer dritten Ausführungsform.

It shows:

Fig. 1

a first state in carrying out the method according to the invention in a first embodiment;

Fig. 2

a second state in carrying out the method according to the invention in a first embodiment;

Fig. 3

a third state in carrying out the method according to the invention in a first embodiment;

Fig. 4

a fourth state in carrying out the method according to the invention in a first embodiment;

Fig. 5

a fifth state in carrying out the method according to the invention in a first embodiment;

Fig. 6

a sixth state in carrying out the method according to the invention in a first embodiment;

Fig. 7

a first state in carrying out the method according to the invention in a second embodiment;

Fig. 8

a second state in carrying out the method according to the invention in a second embodiment;

Fig. 9

a third state in carrying out the method according to the invention in a second embodiment;

Fig. 10

a fourth state in carrying out the method according to the invention in a second embodiment;

Fig. 11

a fifth state in carrying out the method according to the invention in a second embodiment;

Fig. 12

a sixth state in carrying out the method according to the invention in a second embodiment;

Fig. 13

a with the method according to the FIGS. 7 to 12 manufactured end product;

Fig. 14

a in the method according to the FIGS. 7 to 12 used intermediate;

Fig. 15

a first state in carrying out the method according to the invention for the preparation of the intermediate product in a third embodiment;

Fig. 16

a second state in carrying out the method according to the invention for the preparation of the intermediate product in a third embodiment;

Fig. 17

a third state in carrying out the method according to the invention for the preparation of the intermediate product in a third embodiment;

Fig. 18

a fourth state in carrying out the method according to the invention for the preparation of the intermediate product in a third embodiment;

Fig. 19

a fifth state in carrying out the method according to the invention for the preparation of the intermediate product in a third embodiment;

Fig. 20

a sixth state in carrying out the method according to the invention for the preparation of the intermediate product in a third embodiment;

Fig. 21

a first state in carrying out the method according to the invention for the preparation of the final product in a third embodiment;

Fig. 22

a second state in carrying out the method according to the invention for the preparation of the final product in a third embodiment;

Fig. 23

a third state in carrying out the method according to the invention for the preparation of the final product in a third embodiment;

Fig. 24

a fourth state in carrying out the method according to the invention for the preparation of the final product in a third embodiment;

Fig. 25

a fifth state in carrying out the method according to the invention for the preparation of the final product in a third embodiment; and

Fig. 26

a sixth state in carrying out the method according to the invention for the preparation of the final product in a third embodiment.

The FIGS. 1 to 6 show various successive steps or phases in the implementation of a method for producing an in Fig. 6 only partially shown end product 1 from a in Fig. 1 only partially represented intermediate 2 by forming. The further FIGS. 7 to 12 and 21 to 26 show similar or identical processes in which different end products 1 are produced from different intermediate products 2. In Fig. 13 is an example of a final product 1 and in Fig. 14 exemplified an intermediate 2, from which the end product of FIG. 13 was produced. The FIGS. 15 to 20 show the emergence of the intermediate product 2 of a round material, which is subsequently formed in the figures 21 to 26 to the final product 1.

The production of the intermediate product 2, which can preferably take place by means of forming from a blank, not shown, is not shown in the figures. The preparation of the intermediate product 2 by means of deformation from a blank, however, can take place in a manner known per se and easily understandable by the person skilled in the art. Of course, however, other possibilities for the preparation of the intermediate 2 are given. For example, the intermediate product 2 could be produced by primary molding, for example casting or sintering, or optionally also by cutting or stamping or punching.

In all of the in the FIGS. 1 to 6 . 7 to 12 and 21 to 26 illustrated process steps or states of the process, the intermediate product 2 is transformed into the final product 1. Here, the end product 1 in each case at least one projection 1a. At least one preform 2a of the projection 2a to be formed on the end product 1 is provided on the intermediate product 2.

To convert the intermediate product 2 to the end product 1 is a mold 3, which has at least one mold cavity 3a for producing the at least one projection 1a. Preferably, the number of mold cavities 3a corresponds to the number of protrusions 1a to be formed.

At the beginning of the forming, in the method according to the FIGS. 1 to 6 So at the in Fig. 1 2, the intermediate product 2 is positioned opposite the forming die 3 such that the preform 2a is offset from the forming cavity 3a such that in the subsequent forming of the preform 2a to the projection 1a, the material forming the projection 1a at least partially laterally into the mold cavity 3a flows.

In the present case, the intermediate product 2 is positioned relative to the forming tool 3, that when forming the intermediate product 2 to the end product 1, the preform 2a first comes into contact with a surface 3 b of the forming tool 3 which does not belong to the mold cavity 3 a. In the in the FIGS. 1 to 6 In the illustrated embodiment of the method or of the end product 1 to be produced, the surface 3b is a plane surface into which the at least one mold cavity 3a is inserted.

Furthermore, in the illustrated embodiment of the FIGS. 1 to 6 the intermediate product 2 is positioned opposite to the forming tool 3 immediately before the forming such that the preform 2 a is arranged at least approximately completely next to and immediately adjacent to the mold cavity 3 a. In the case of a geometry of a different kind, however, there may also be an at least partially existing overlapping of these regions.

Through this positioning and the subsequent application of force in the Fig. 2 With "z" designated direction of the forming tool 3 to the intermediate product 2, the intermediate product 2 is deformed. As a result of the described positioning, the material of the preform 2a flows at least partially into the in Fig. 2 with "x" designated lateral direction in the mold cavity 3 a, which by the individual states or phases of the deformation in the FIGS. 2, 3, 4, 5 and finally the final state of Fig. 6 is very recognizable. Here, the direction "x" is substantially perpendicular to the direction "z".

The described method has combined characteristics of the transverse extrusion and the backward extrusion in one operation. This can be taken from all the embodiments of the method in a simple manner from the figures.

The described method leads to a reduction of the pressing force required for the deformation, which leads to a lower load on the forming tool 3. This reduction in the required pressing force results, in particular, from the design of the preform 2a, which is not formed, as usual, as a flat surface but similar to the projection 1a formed therefrom, as well as the arrangement described above relative to the forming tool.

The forming of the end product 1 from the intermediate product 2, which is shown in FIGS. 1 to 6, can be carried out in a forming step immediately following the forming of the intermediate product 2 from the blank. The forming tool 3 can be part of a follow-up tool not shown in its entirety. In such a follower tool precautions should be taken to ensure the above-described positioning of the intermediate product 2 with respect to the forming tool 3. Basic solutions to this can be found in the general state of the art.

In the embodiments shown in all figures, the projection 1a has a tooth shape and is part of a toothing 4 of the end product 1. In the present case, the toothing 4 is a spur toothing, as in FIG Fig. 13 exemplified end product 1 is recognizable. For example, such spur gears can be used on chassis components of motor vehicles to prevent rotation.

The transformation of the intermediate 2 to the final product 1 is carried out in all the methods described herein by means of cold massive forming. In principle, however, it would also be possible to use a hot forming process for the transformation of the intermediate product 2 into the end product 1.

While at the in the FIGS. 1 to 6 illustrated embodiment, each preform 2a leads to exactly one projection 1a, in the embodiment of the FIGS. 7 to 12 each preform 2a has a shape corresponding to two teeth. In this case, two projections 1a forming teeth of the teeth 4 are formed from each preform 2a. This in Fig. 13 shown end product 1 was with the in the FIGS. 7 to 12 produced, ie corresponds to the state of Fig. 12 , and that in Fig. 14 represented intermediate 2 was used as the starting material for this, ie corresponds to the state of Fig. 7 ,

The positioning of the intermediate product 2 before or during the conversion to the end product 1 in the initial state of Fig. 7 corresponds in principle to the positioning according to Fig. 1 , so that here too, the material 1a forming the projection of the intermediate product 2 at least partially flows laterally into the mold cavity 3a. In contrast to the embodiment according to the FIGS. 1 to 6 however, the material of a preform 2a flows into two mold cavities 3a. As in Fig. 12 can be seen, results in this way, a very good filling of the mold cavities 3a.

The FIGS. 15 to 20 show the forming process for the production of in Fig. 21 represented preform 2a of a round material. In the FIGS. 21 to 26 is one of the embodiment of the FIGS. 1 to 6 shown very similar method, wherein it is not a spur toothing, but a arranged on the circumference of the end product 1 gear 4 is in the toothing produced therewith. As in the embodiment of FIGS. 7 to 12 For example, the preform 2a has a shape corresponding to two teeth, and two teeth of the teeth 4 are formed from each preform 2a. The in the FIGS. 7 to 12 and 21 to 26 illustrated embodiment of the intermediate product 2 is particularly advantageous at a high tooth density of the toothing 4.

Although in the embodiments described herein, the projection 1a each has a tooth shape, it is also conceivable with the described method differently shaped end products 1, ie end products 1 with different types of protrusions 1a.

In the embodiments described herein, in the process of forming the intermediate product 2 into the final product 1, only the preform 2a is transformed into the projection 1a. However, it is also possible to mold additional elements on the intermediate product 2 during this forming process.

In the case of tubular components, the preform 2a on the inner and outer diameters can also be designed differently depending on the desired tooth geometry in order to image the respective tooth over the entire radius profile and to ensure homogeneous mold filling.

Claims (10)

Process for the preparation of a final product (1) from an intermediate (2) by means of transformation, comprising the following process steps: Producing the intermediate product (2) which has at least one preform (2a) of at least one projection (1a) to be formed on the end product (1), - forming the intermediate product (2) to the end product (1) having the at least one projection (1a) by means of a forming tool (3) having at least one mold cavity (3a) for producing the at least one projection (1a), characterized in that
the intermediate product (2) is positioned opposite to the forming tool (3) during the forming of the end product (1) so that the preform (2a) is offset from the mold cavity (3a) such that during the forming of the preform (2a) the protrusion (1a) the material forming the projection (1a) flows at least partially laterally into the mold cavity (3a). Method according to claim 1,
characterized in that
positioning the intermediate product (2) with respect to the forming tool (3) so that, when the intermediate product (2) is formed into the final product (1), the preform (2a) is first provided with a surface (3b) not belonging to the mold cavity (3a) of the forming tool (3) comes into contact. Method according to claim 1 or 2,
characterized in that
the intermediate product (2) is positioned relative to the forming tool (3) in such a way that the preform (2a) is arranged at least approximately completely next to and immediately adjacent to the mold cavity (3a). Method according to claim 1, 2 or 3,
characterized in that
the intermediate product (2) is produced from a blank by means of forming. Method according to claim 4,
characterized in that
the forming of the end product (1) from the intermediate product (2) is carried out in a forming step immediately following the forming of the intermediate product (2) from the blank. Method according to one of claims 1 to 5,
characterized in that
the at least one projection (1a) has a tooth form and is part of a tooth system (4). Method according to claim 6,
characterized in that
the at least one preform (2a) has a shape corresponding to two teeth, wherein two teeth of the toothing (4) are formed from each preform (2a). Method according to claim 6 or 7,
characterized in that
the toothing (4) is a spur toothing. Method according to one of claims 1 to 8,
characterized in that
the forming of the intermediate (2) into the final product (1) is carried out by cold working. Apparatus for carrying out the method according to one of claims 1 to 9, having a forming tool (3) having at least one mold cavity (3a) for forming the at least one projection (1a).

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