EP1347849B1 - Flowspinning method and device for carrying out flowspinning - Google Patents

Description

The invention relates to a flow-forming method according to The preamble of claim 1 and a device for Pressure rollers according to the preamble of claim 10.

In a generic flow-forming process is a blank arranged on a rolling mandrel of a flow-forming machine, the blank relative to at least one spinning roller in Rotation offset, the at least one spinning roller relative delivered to the blank and the blank through the Flow-forming roller axially elongated and press-rolled to a workpiece.

A generic flow-forming process is known from DE-A-34 02 301 known. In this method can on the spinning roller radial, axial and tangential force components be measured. The measured values are used for Control of the flow-forming process.

A generic device for spin forming has a Rolling mandrel for picking up a workpiece, at least one Flow-forming roller, a drive device for generating a Rotation between the workpiece and the spinning roller and a control device for controlling a delivery relatively between Rolling mandrel and spinning roll on. Such a device is also known from DE-A-34 02 301.

It can be driven to rotate the roll mandrel and the flow-forming roller radially and / or axially to the workpiece be delivered. But it is also possible that a rotating driven spinning roller or a plurality of spinning rolls, which are driven on a rotating Wreath are arranged radially and / or axially to a fixed or likewise rotatingly driven rolling mandrel be delivered.

Such methods and apparatus for spin forming are and are known, for example, for cylinder-spinning used by rotationally symmetrical precision hollow parts.

These known methods are characterized by special Profitability, which is essentially justified in material savings due to non-cutting forming, in the strain hardening of the material during forming and in the opposite to cutting procedures considerably shorter production times. In addition, can be with make these methods a variety of outer shell molds, For example, contour heels, transition radii and conical areas possible.

In cylinder spinning, wall thickness tolerances can be achieved of a few hundredths of a millimeter. The usual However, inserted cylindrical blanks point in usually several tenths of a millimeter thickness tolerances. Due to the individually different thickness of the blanks thus result due to the volume constancy of the reshaped Material considerable geometry, in particular Length differences, on the finished part. There will be more Machining steps, in particular machining finishing, required. This increases significantly the machine, personnel, time and material costs and thus the costs for the finished precision parts.

The object of the invention is to provide a method and a device with which workpieces can be manufactured with particularly high precision.

This task is performed by a procedure with the characteristics of claim 1 and by a device with the features of claim 10 solved.

Preferred developments of the method according to the invention and advantageous embodiments of the invention Device are claimed in the subclaims.

A method of the type indicated above is according to the invention further developed in that to compensate for dimensional fluctuations the blank at least one compensation area in the Workpiece is formed that before and / or during the Drückwalzens with a measuring device geometric data of the blank or the workpiece are determined that the Achieving a desired final geometry of the workpiece geometric parameters of the at least one compensation area depending on the determined geometric data be calculated individually and that by means of a control device the delivery of the spinning roller accordingly the calculated geometric parameters of the compensation area is controlled so that regardless of dimensional variations of the blank a workpiece with the desired final geometry is formed.

As a core idea of the invention can be considered that each blank depending on the actual dimensional fluctuation individually made. For this purpose, the invention before and / or during spin-rolling geometric data of the blank or the workpiece determined. Subsequently, based on this geometric Data an individual compensation area in the Workpiece incorporated. It can thus be the significant advantage be achieved that, regardless of any present Dimensional variations of the blank, the workpiece always has a desired end geometry.

Another significant advantage is that with the inventive method workpieces with so high Precision can be made that subsequent processing steps, especially post-processing, can be omitted. This will save time, Personnel and machine expenses made possible to a large extent.

In a preferred embodiment of the method is the at least one compensation area in one for a functionality of the workpiece uncritical area of the workpiece incorporated. As a result, the advantage can be achieved Be that functionality of the workpieces, regardless of how the compensation area individually is formed, is preserved.

As geometric data, preferably at least one axial length of the blank or of the workpiece, in particular be determined several times. As the wall thickness of the workpiece when rolling out mostly significantly reduced, the workpiece So strong is lengthened, the axial length depends sensitive of any dimensional variations of the blank so that due to this size the geometric Parameters of the compensation area are determined very accurately can.

With the aid of suitable position measuring systems, their measured data be processed by a central computer So according to the invention in the ongoing manufacturing process master occurring wall thickness tolerances.

It can also be a geometric data but also a diameter and / or a wall thickness of the blank or of the workpiece be determined. This can improve the accuracy of the determination the compensation area parameter is increased.

In addition to the geometric data, further measurements on Blank or on the workpiece to be performed. For example can before, during and / or after the spin forming a Temperature of the workpiece to be determined.

In addition, during the spin-forming also a pressure in the workpiece, in particular in the axial direction determined become.

Of pressure and temperature depends the concrete geometry of the Workpiece sensitive, leaving a record of this Parameter a further increase in manufacturing precision allows.

Preferably, the determined temperature and / or the determined pressure supplied to the computer device and go into the calculation of the geometric parameters of the compensation area.

In a preferred variant of the method according to the invention the compensation area becomes a cylindrical area and / or as at least one bevelled area, shaped. These forms are on the one hand in a simple manner a flow-forming machine produced and also can geometric parameters of these forms in a particularly simple Be calculated way.

Depending on the design of the workpiece but can also other, in principle arbitrarily shaped compensation areas will be realized.

If the dimensional variations of the blanks are particularly large, can be provided that several compensation area in the Workpiece to be incorporated. This can also be beneficial if desired, that is the variation of geometric Parameters of a compensation area of workpiece to workpiece should not be too big.

The inventive method can as synchronous and also be carried out as a mating method.

A device of the type specified above is according to the invention further developed by the fact that at least one measuring device for determining geometric data of the workpiece is provided that the measuring device with a Computer device is connected to the calculation of geometric parameters of a compensation range is, which for individual compensation of Maßschwankungen of the blank incorporated into the workpiece is, and that by means of the control device, the delivery the spinning roller is controllable, so that the compensation area of the workpiece as a function of the Computer device individually calculated geometric Parameter is formed.

The device, also referred to as a flow-forming machine can be operated web and / or pressure controlled become. With the help of NC technology, pioneers can be found Flow-forming operations as well as the exact positioning realize the spinning rollers in the longitudinal and transverse axis.

Preferably, the measuring device has at least one Displacement sensor on. This may be an optical, acoustic and / or a sensor for determining the electrical Conduct conductivity.

In an advantageous embodiment of the invention Device are provided a plurality of displacement sensors, which in particular axially spaced from each other. This advantageously allows a multiple determination, for example, an axial length of the workpiece, in the course of the flow-forming process.

To increase the information base for the calculation the geometric parameter of the compensation area can but also be provided that the measuring device a Sensor for determining a diameter of the workpiece and / or a wall thickness of the workpiece.

In addition, gauges or sensors can be used to determine be provided further physical quantities, so that the Workpiece more accurately characterized and the manufacturing process carried out under even better defined conditions can be.

For example, to determine a temperature of Workpiece a temperature sensor or it can be used for determination a pressure in the workpiece, in particular in an axial Direction, a pressure sensor may be provided.

Further features, properties and advantages of the invention Method and the inventive device will be described below with reference to the schematic Drawings explained.

Fig. 1

eine axiale Querschnittsansicht eines Rohlings;

Fig. 2 bis 4

axiale Querschnittsansichten von Werkstücken, welche aus Rohlingen mit unterschiedlichen Maßschwankungen drückgewalzt wurden;

Fig. 5 bis 7

axiale Querschnittsansichten von Werkstücken mit individuell ausgebildeten Ausgleichsbereichen;

Fig. 8 bis 10

axiale Querschnittsansichten von weiteren Werkstücken mit individuell ausgebildeten Ausgleichsbereichen;

Fig. 11

schematische Teilquerschnittsansichten eines Rohlings bzw. eines Werkstücks sowie einer erfindungsgemäßen Vorrichtung in unterschiedlichen Stadien des erfindungsgemäßen Verfahrens;

Fig. 12

schematische Teilquerschnittsansichten eines weiteren Rohlings bzw. eines weiteren Werkstücks sowie der erfindungsgemäßen Vorrichtung aus Fig. 11 in unterschiedlichen Stadien des erfindungsgemäßen Verfahrens; und

Fig. 13

schematische Teilquerschnittsansichten eines weiteren Rohlings bzw. eines weiteren Werkstücks sowie der erfindungsgemäßen Vorrichtung aus Fig. 11 in unterschiedlichen Stadien des erfindungsgemäßen Verfahrens.

In these drawings show:

Fig. 1

an axial cross-sectional view of a blank;

Fig. 2 to 4

axial cross-sectional views of workpieces that have been spin-rolled from blanks having different dimensional variations;

Fig. 5 to 7

axial cross-sectional views of workpieces with individually formed compensation areas;

Fig. 8 to 10

axial cross-sectional views of other workpieces with individually trained compensation areas;

Fig. 11

schematic partial cross-sectional views of a blank or a workpiece and a device according to the invention in different stages of the method according to the invention;

Fig. 12

schematic partial cross-sectional views of another blank or another workpiece and the inventive device of Figure 11 in different stages of the method according to the invention. and

Fig. 13

schematic partial cross-sectional views of another blank or another workpiece and the inventive device of FIG. 11 in different stages of the method according to the invention.

Figure 1 shows an axial cross-sectional view of a tubular Blank 12 with an axial length Lo, an inner diameter di, an outer diameter there and with a Wall thickness So. The dimensions indicated in the figures are to be understood in millimeters.

The wall thickness So of the blank 12 has a tolerance of +/- 0.12 mm.

As illustrated by the following figures 2 to 4, This tolerance drastically affects one axial length L1 of a finished workpiece 14.

Figure 2 shows in an axial cross-sectional view of a a blank 12 rolled in an axial direction Z. Workpiece 14. The wall thickness So of the blank used in this case 12 was at the lower limit of the tolerance range FIG. 1

In Figures 3 and 4 are in axial cross-sectional views further workpieces 14 shown in which the Wall thickness So the blanks used 12 in the middle or at the upper edge of the tolerance range of Figure 1 were.

Figures 2 to 4 can be taken very clearly, that individually present Maßschwankungen the blanks 12, in the case shown here, the fluctuation of the wall thickness So, very strong on the geometry, about the axial Length L1 of the rolled workpieces 14 impact. For example differs the axial length L1 of the Workpiece 14 of Figure 2 compared to the workpiece Figure 4 by almost 8%.

In Figures 5 to 7 are in axial cross-sectional views Workpieces 14 shown in which in a for a functionality of the workpiece 14 non-critical area according to the invention compensation areas 26 individually were incorporated.

The compensation regions 26 each have a cylindrical Area A as well as a run-out slope X1, X2, X3 trained beveled area on. All workpieces 14 of Figures 5 to 7 have an identical design cylindrical region L between that in Figures 5 to 7 right end of the workpiece 14 and the compensation area 26 on. Furthermore, in the workpieces 14 of Figures 5 to 7 is a cylindrical area A with an identical axial Length and an identical wall thickness S2 formed.

To compensate for dimensional variations of each used Blanks 12 are the outlet slopes X1, X2, X3, which starting from point Y to the cylindrical area A connect, individually trained.

For the workpiece 14 of Figure 6, a blank 12 was used, where the wall thickness So in the middle of the tolerance range from Figure 1 was. The workpieces 14 in FIG 5 and 7, however, were from blanks 12 with wall thicknesses So at the upper or at the lower end of the tolerance range from FIG 1 press-rolled.

According to the lying above the average wall thickness Thus, the blank 12 used has the workpiece 14 of Figure 5 a with respect to the axial extent of Outlet slope X2 from Figure 6 shortened outlet slope X1 on. Analog is the outlet slope X3 of the workpiece 14, for which a blank with a below average Wall Thickness So used was extended compared to X2.

To a manufacturing end length L1 of the workpieces 14 despite the occurring dimensional variations of the blanks 12 to constant hold, are thus according to the invention compensation areas 26, which are also referred to as tolerance compensation ranges can, in the manufacture or construction of workpieces 14 or production parts considered. In these balancing areas 26 tolerance differences are accordingly their effect on the final production length L1 Considering measuring during the forming process.

Also, a subsequent mechanical processing to the Opening diameters exactly in the axial total length L1 to be taken into account.

In the outlet slopes shown in Figures 5, 6 and 7 X1, X2, X3 becomes at the point Y, which always the has the same distance to the right opening diameter, made a measurement on the ironed part. Considering the travel path of a spindle in the Z direction calculates a calculator over a volume equation the Ist deviation and thus defines the axial extent of the Outward slopes X1, X2, X3 fixed.

The volume equation used is the volume constancy of the formed material as well as the constancy of the Inside diameter of the workpiece.

As a result, by the incorporation of the invention of individually trained compensation areas 26 workpieces 14 achieved with identical axial lengths L1.

Further examples of customized compensation areas 26 are shown in FIGS. 8-10. Here again are workpieces 14 in axial cross-sectional views shown, which starting from blanks 12 with different Wall thickness So with the method according to the invention were made.

As in FIGS. 5 to 7, the workpieces 14 each have identical ones cylindrical areas L on, each one individually connect trained compensation areas 26. The compensation areas 26 in turn each consist of one cylindrical area A1, A2, A3 and a itself after point Y subsequent outlet slopes X1, X2 and X3.

In contrast to the workpieces 14 of Figures 5 to 7 were at the workpieces 14 of Figures 8 to 10 both the outlet slopes X1, X2, X3 and the cylindrical Areas A1, A2, A3 of the compensation areas 26 individually to the respective dimensional fluctuation of the used Blank 12 adapted.

Again, identical axial lengths L1 of the completed Workpieces 14 achieved.

Examples of making weight-optimized wheels, which are produced in the counter-flow-forming process, the invention will continue in FIGS. 11, 12 and 13 explained.

When counter-rotating spin forming is a blank 12, in which it may be a rifle or pipe section, pushed over a rolling mandrel 16 to a clamping point and there detected by a driving ring 42, with hardened teeth can be provided.

An axial force of one or more spinning rollers 18 presses the blank 12 on a toothed segment and offset him thereby in a rotary motion. The material flows in the forming under the flow-forming rollers 18 in the direction of the free rolling mandrel and beyond that into a free one Working space of the machine. Longitudinal feed and flow direction are thus opposing each other.

However, this invention for pushers and others Flow-turning operations are used. Also combinations of length, diameter, pressure and temperature measurements are possible depending on the application.

In the figures 11, 12 and 13 are parts of an inventive Device as well as in partial cross-sectional views blanks 12 and workpieces 14 at different stages of the invention Process illustrated. The blanks 12 of Figures 11, 12 and 13 each have different Wall thicknesses up.

Identical components are each given the same reference numerals characterized.

The partial cross-sectional views of method step 1 show each one angeordenten on a rolling mandrel 16 blank 12, which comes with a driving ring 42 into abutment. It Then, the rolling mandrel 16 is driven in rotation and several Flow-forming rollers 18, one of which is exemplified is radially delivered to the blank 12.

The axial feed takes place by moving the rolling mandrel in the Z direction.

To determine the axial length of the workpiece in different Stages of the method according to the invention are on the device a plurality of displacement sensors 46, 48, 50, 52 are provided. These displacement sensors 46, 48, 50, 52, in which there in particular may be optical sensors are axially spaced from each other at positions Z1, Z2, Z3, Z4 arranged.

First, with the help of the flow-forming rollers 18 in the workpiece 14 a region 28 incorporated with reduced wall thickness. Through this area 28 is together with a later to be formed compensation area 26 in the finished Workpiece 14 an approximately symmetrical mass distribution achieved.

On the basis of the displacement sensors 46, 48, 50, 52 in the course the spin forming determined axial lengths of the workpiece 14 according to the invention, the geometric parameters of Compensation area 26 individually calculated and the flow-forming rollers 18 are calculated according to the calculated parameters axially and radially delivered to the workpiece 14.

Overall, when rolling out of the blank 12 to the finished Workpiece 14 of the driving ring 42 by a Gesamtverfahrweg delivered in the Z direction 44 relative to the flow-forming roller 18.

In step 1, the flow-forming roller 18 in a Distance of 32.3 mm from the right opening diameter attached. In step 2, a first run-up slope of the area 28 trained.

In step 3, the spinning roller 18 is in a cylindrical portion of the area 28, wherein at a distance of 63.87 mm from the spinning roller 18 at the position Z1 the displacement sensor 46 is arranged as the first measuring point. Subsequently, a discharge slope of the area 28 in the Formed workpiece 14.

In step 4 is a discharge ramp of 8.18 mm in length finished molded. In step 5, the workpiece 14 has the reached at the position Z2 arranged second transducer 48. At a distance of 98.7 mm begins a first inlet slope a compensation area 26 except for a wall thickness cross section of 1.92 mm.

In step 6, the workpiece 14 has the third position transducer 50 is reached at the position Z3, which is at a distance of 167.9 mm from the flow-forming roller 18 is located. It is now measured by a calculator based on the measured Track in Z-direction and taking into account the measured data of the transducer 50 at position Z3 via the volume equation the parameters for an outlet slope of the Compensation area 26 determined to a total workpiece length of 204.5 mm. At the same time, from the determined data position Z4 a fourth, variable positionable position transducer 52 set.

With the help of the fourth displacement sensor 52 at the position Z4 can be a desired axial end length of the finished Workpiece 14 are verified.

In step 7 is on reaching the fourth transducer 52 terminated at the position Z4 of the flow-forming and the Workpiece 14 has reached its desired length of 204.5 mm.

In Figures 12 and 13 is the inventive method in an analogous manner as in Figure 11 for blanks 12 with represented different Maßschwankungen. The process steps Figures 1 to 8 of Figures 12 and 13 correspond to those of Figure 11, which is why a detailed description is omitted here.

For the various blanks 12 of Figures 11, 12 and 13, each having different initial dimensions, are in turn result in workpieces 14 with identical achieved axial length.

Claims (15)

1. Flow-forming method, in which

   a blank (12) is placed on a rolling mandrel (16) of a flow-forming machine,

   the blank (12) is rotated relative to at least one flow-forming roll (18),

   the at least one flow-forming roll (18) is infed relative to the blank (12) and

   the blank (12) is axially lengthened by the flow-forming roll (18) and flow-formed to a workpiece (14),

   characterized in that

   for compensating dimensional variations of the blank (12) at least one compensating area (26) is worked into the workpiece (14),

   before and/or during flow-forming a measuring device determines geometrical data of the blank (12) and/or workpiece (14),

   for obtaining a desired final geometry of the workpiece (14), the geometrical parameters of the at least one compensating area (26) are individually calculated as a function of the geometrical data determined and

   by means of a control device the infeed of the flow-forming roll (18) is controlled in accordance with the calculated geometrical parameters of the compensating area (26), so that a workpiece (14) with the desired final geometry can be formed independently of dimensional variations of the blank (12).
2. Method according to claim 1,
   characterized in that
   the at least one compensating area (26) is worked into an area of the workpiece (14) non-critical for the functionality of the latter.
3. Method according to one of the claims 1 or 2,
   characterized in that
   as geometrical data determination takes place of at least one axial length (L0; L1) of the blank (12) and/or workpiece (14), more particularly several times.
4. Method according to one of the claims 1 to 3,
   characterized in that
   as geometrical data determination takes place of a diameter (da) and/or a wall thickness (S0; S1) of the blank (12) and/or workpiece (14).
5. Method according to one of the claims 1 to 4,
   characterized in that
   before, during and/or after flow-forming a temperature of the workpiece (14) is determined.
6. Method according to one of the claims 1 to 5,
   characterized in that
   during flow-forming a pressure is determined in the workpiece (14), particularly in the axial direction (Z).
7. Method according to one of the claims 5 or 6,
   characterized in that
   the determined temperature and/or pressure is supplied to the computer means and enters the calculation of the geometrical parameters of the compensating area (26).
8. Method according to one of the claims 1 to 7,
   characterized in that
   the compensating area (26) is formed as a cylindrical area (A; A1; A2; A3) and/or at least one bevelled area (X1; X2, X3).
9. Method according to one of the claims 1 to 8,
   characterized in that
   several compensating areas (26) are worked into the workpiece (14).
10. Apparatus for flow-forming having

    a rolling mandrel (16) for receiving a workpiece (14),

    at least one flow-forming roll (18),

    a driving device for producing a rotation between workpiece (14) and flow-forming roll (18) and

    a control device for controlling an infeed of relative nature between rolling mandrel (16) and flow-forming roll (18),

    characterized in that

    at least one measuring device is provided for determining geometrical data of the workpiece (14),

    the measuring device is connected to a computer means designed for calculating the geometrical parameters of a compensating dimensional variations of the blank (12) and

    by means of the control device the infeed of the flow-forming roll (18) can be controlled, so that the compensating area (26) of the workpiece (14) is constructed as a function of the geometrical parameters individually calculated by the computer means.
11. Apparatus according to claim 10,
    characterized in that
    the measuring device has at least one displacement transducer (46, 48, 50, 52).
12. Apparatus according to claim 11,
    characterized in that
    several displacement transducers (46, 48, 50, 52) are provided and are in particular arranged in axially spaced manner.
13. Apparatus according to one of the claims 10 to 12,
    characterized in that
    the measuring device has a sensor for determining a diameter of the workpiece (14) and/or a wall thickness (S1) of the workpiece (14).
14. Apparatus according to one of the claims 10 to 13,
    characterized in that
    a temperature sensor is provided for determining a temperature of the workpiece (14).
15. Apparatus according to one of the claims 10 to 14,
    characterized in that
    a pressure sensor is provided for determining a pressure in the workpiece (14), particularly in an axial direction (Z).

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