DE102015004886A1 - Pulling shaft and drawing roller for a wire drawing machine - Google Patents

Abstract

The invention relates to a pulling shaft 1 and a drawing roller 2 for a wire drawing machine, wherein the pulling shaft 1, an outer connecting means 3 and the drawing roller 2 has an axial bore 6 and an inner, arranged in the axial bore 6 connecting means 4. The two connecting means 3, 4 are provided for producing a positive connection with each other, which is given when the axes of rotation 13, 14 of the pulling shaft 1 and the drawing roller 2 coincide and the outer connecting means 3 of the pulling shaft 1 engages in the inner connecting means 4 of the drawing roller 2 , According to the invention, the outer connecting means 3 of the pulling shaft 1 and the space surrounded by the inner connecting means 4 in the axial bore 6 of the drawing roller 2 each have a convex non-circular cross sectional area 11, 12 perpendicular to the axis of rotation 13, 14 of the pulling shaft 1 or at least one point of the drawing roller 2. Due to the convexity of the two cross-sectional surfaces 11, 12, the radial distance between the radially innermost and the radially outermost point of the circumferential lines 9, 10 of each cross-sectional surface 11, 12 can be made very small. Thus, the positive connection can also be used for a drawing roller 2 with a small wall thickness, without the wall of the drawing roller 2 is weakened too much.

Description

The invention relates to a pulling shaft and a drawing roller, which are intended for use in a wire drawing machine, with connecting means for producing a positive connection between the drawing shaft and the drawing roller.

In a wire drawing machine, the wire to be drawn is typically passed through an opening in a so-called die, which has a diameter slightly smaller than the diameter of the wire. Then, the wire is guided to a drawing roller and wrapped around the drawing roller by a certain angle, in particular in several turns. The wire preferably runs in a circular groove on the surface of the drawing roller.

In this way, the wire is set in tension by the rotating drawing roller by the friction between the wire and the surface of the drawing roller and the diameter of the tensioned wire is slightly reduced as it passes through the opening of the drawing die. By a series connection of several dies and drawing rollers, the wire diameter can be reduced to a desired total value.

In a multi-wire drawing machine, a plurality of wire sections can also be guided in parallel over the same drawing roller, preferably in separate circular grooves, thereby correspondingly increasing the productivity of the machine. However, the present invention is not limited to the use of the drawing shaft and the drawing roller in a single-wire or a multi-wire drawing machine.

The drawing roller preferably has a cylindrical basic shape and has an axial, continuous or blind bore. In this hole, a pulling shaft is inserted, which protrudes axially beyond this at one or both ends of the drawing roller and over which the drive of the drawing roller takes place during operation of the drawing machine. In the assembled state, the axes of rotation of the drawing shaft and the drawing roller coincide. The pulling shaft and the drawing roller are positively coupled so that driving torque can be transmitted from the pulling shaft to the pulling roller while the pulling shaft and the pulling roller rotate about their common rotation axis.

Such a two-part embodiment of a drive assembly for a wire drawing machine, consisting of the drawing shaft and the drawing roller, is advantageous because the drawing roller can be replaced independently of the drawing shaft as soon as it is worn.

To produce the positive connection, the pulling shaft has an outer connecting means, i. H. a connecting means disposed on the outer surface of the pulling shaft. Accordingly, the drawing roller in its axial bore on an inner connecting means, d. H. a connecting means, which is arranged on the inner surface of the drawing roller.

The positive connection between the drawing shaft and the drawing roller is then achieved in that the outer connecting means of the pulling shaft engages in the inner connecting means of the drawing roller. In this way, a driving torque can be transmitted from the pulling shaft to the drawing roller.

In conventional drive assemblies for wire drawing machines, the positive connection between the drawing shaft and the drawing roller is often realized by a feather key connection. The key is inserted in an axial groove on the outer surface of the pulling shaft and forms the outer connecting means of the pulling shaft. During assembly of the drawing shaft and the drawing roller, the feather key engages in a further axial groove on the inner surface of the drawing roller, which forms the inner connecting means of the drawing roller. The drive torque is then transmitted from the pull shaft via the feather key to the draw roll.

The present invention has for its object to provide an improved drawing shaft and an improved drawing roller for a wire drawing machine, a combination of such a drawing shaft and drawing roller and a manufacturing method for such a drawing shaft and drawing roller.

This object is achieved by the drawing shaft according to claim 1, the drawing method of the drawing shaft according to claim 6, the drawing roller according to claim 7, the manufacturing method for the drawing roller according to claim 12 and the combination of the drawing shaft and the drawing roller according to claim 13. Advantageous embodiments of the invention included in the subclaims.

The invention is based on the observation that the key used in conventional drive assemblies must have a relatively large extent in the radial direction in order to be able to transfer the drive torque from the pull shaft, which can become very large in a wire drawing machine, safely to the drawing roller. At the same time, the drawing shaft often has a relatively large outer diameter compared to the outer diameter of the drawing roller, d. H. the drawing roller has only a relatively small wall thickness. In this case, the wall of the drawing roller is greatly weakened in the region of the axial groove for receiving the key in a feather key connection.

The invention is based on a pulling shaft with an outer connecting means and a drawing roller with an axial bore and an inner, arranged in the axial bore connecting means. Here, the outer connecting means of the pulling shaft and the inner connecting means of the drawing roller are provided for producing a positive connection with each other, wherein the positive connection is given when the axis of rotation of the drawing shaft and the axis of rotation of the drawing roller coincide and the outer connecting means of the pulling shaft in the inner connecting means of the Pulling roller engages.

According to the invention, the outer connecting means of the pulling shaft at at least one point on a convex, non-circular cross-sectional area perpendicular to the axis of rotation of the pulling shaft.

Accordingly, the space surrounded by the inner connecting means in the axial bore of the drawing roller according to the invention has at least one point in a convex, non-circular cross-sectional area perpendicular to the axis of rotation of the drawing roller.

A convex surface is here in the usual mathematical sense a surface without "indentations", d. H. that for every two arbitrary points in the surface, their connection distance lies entirely within the surface.

Thus, both the outer connecting means of the pulling shaft and the inner connecting means of the drawing roller have a convex, non-circular profile, by the term "profile" the circumferential line of the cross-sectional area of the respective connecting means is meant. The two profiles are geometrically designed so that the profile of the outer connecting means penetrates the profile of the inner connecting means at one, in particular already at a slight, rotation about the common center of the two profiles (which corresponds to the common axis of rotation of the pulling shaft and the drawing roller). So with this "collided" and this "rotates" during rotation, resulting in the desired positive connection between the pull shaft and the drawing roller.

The fact that the two profiles are convex and thus have no "indentations" in the radial direction, the radial distance between the radially innermost and the radially outermost point of each profile can be chosen very small. As a result, the two profiles can also be used for a positive connection between a pulling shaft and a drawing roller when the drawing roller has a small wall thickness, without the wall of the drawing roller is weakened too much.

Preferably, the inner and / or the outer connecting means is formed in each case as an axial portion on the drawing shaft or on the drawing roller, wherein the two sections preferably have the same axial extent and preferably come to lie in the assembled drive assembly in the same axial region. The two above-defined, convex cross-sectional surfaces in the region of the two connecting means also preferably come to lie in the assembled drive assembly at the same axial location. Preferably, the cross-sectional area of the respective connecting means within the respective section is constant, but may also vary along the axial extent of the respective section, in particular constantly become larger or constantly smaller. Preferably, at least one of the two sections and particularly preferably both sections are conical.

In a preferred embodiment of the invention, the cross-sectional area of the outer connecting means of the drawing shaft and the inner connecting means of the drawing roller is rotationally symmetric, d. H. the cross-sectional area, by virtue of a rotation about its center point, which corresponds to the axis of rotation of the drawing shaft or of the drawing roller, passes over itself geometrically by at least an angle which is greater than 0 degrees and less than 360 degrees.

Preferably, this angle is 360 degrees / n, where n is a natural number greater than 1. In this case we also speak of an n-fold rotational symmetry. Particularly preferably, the cross-sectional area has a three-, four-, five- or six-fold or an n-fold (with n greater than 6) rotational symmetry.

Due to the rotational symmetry, the outer connecting means of the pulling shaft can engage in several (with n-fold rotational symmetry in n different) rotational positions in the inner connecting means of the drawing roller, which facilitates the assembly of the drive assembly of the drawing shaft and the drawing roller. In addition, the rotational symmetry facilitates the production of the profiles of the connecting means, in particular in a CAD / CAM environment.

In a further preferred embodiment of the invention, the circumferential line of the cross-sectional area has no kinks. This has the advantage on the one hand that no notch effect with a concomitant stress concentration at such kinks can occur during the mechanical loading of the connecting means. In addition, in this way the risk of tilting between the two connection means is prevented. Also, the preparation of the connecting means in this case in a simple manner Grinding, take place in the inner connecting means in particular by internal cylindrical grinding.

In a further preferred embodiment of the invention, the cross-sectional area in the form of a square with outwardly curved side edges and with convex curves in the transition region of the side edges, in particular with rounded corners, which combines the advantages mentioned above.

• – das Verhältnis des Durchmessers des kleinsten Kreises mit Mittelpunkt auf der Rotationsachse der Ziehwelle, welcher die oben definierte Querschnittsfläche des äußeren Verbindungsmittels der Ziehwelle enthält, zum Durchmesser des größten Kreises mit Mittelpunkt auf der Rotationsachse der Ziehwelle, welcher in dieser Querschnittsfläche enthalten ist, bzw.
• – das Verhältnis des Durchmessers des kleinsten Kreises mit Mittelpunkt auf der Rotationsachse der Ziehwalze, welcher die oben definierte Querschnittsfläche des von dem inneren Verbindungsmittel umgebenen Raumes in der axialen Bohrung der Ziehwalze enthält, zum Durchmesser des größten Kreises mit Mittelpunkt auf der Rotationsachse der Ziehwalze, welcher in dieser Querschnittsfläche enthalten ist,

kleiner oder gleich 1,25; vorzugsweise kleiner oder gleich 1,2; weiter vorzugsweise kleiner oder gleich 1,15; noch weiter vorzugsweise kleiner oder gleich 1,1.In a further preferred embodiment of the invention

• - The ratio of the diameter of the smallest circle with the center on the axis of rotation of the drawing shaft, which contains the above-defined cross-sectional area of the outer connecting means of the drawing shaft, to the diameter of the largest circle centered on the axis of rotation of the drawing shaft, which is included in this cross-sectional area, or
• The ratio of the diameter of the smallest circle centered on the axis of rotation of the drawing roll, containing the above-defined cross-sectional area of the space enclosed by the internal connecting means in the axial bore of the drawing roll, to the diameter of the largest circle centered on the axis of rotation of the drawing roll contained in this cross-sectional area,

less than or equal to 1.25; preferably less than or equal to 1.2; more preferably less than or equal to 1.15; even more preferably less than or equal to 1.1.

In this way, a positive connection between the drawing shaft and the drawing roller can be realized even with a drawing roller with a small wall thickness, without weakening the wall of the drawing roller too much. In addition, this makes it possible - starting from semi-finished products for the drawing shaft or the drawing roller with a cylindrical outer or inner surface in the region of the respective connecting means - the connecting means without large material removal and thus inexpensively and quickly, in particular by grinding or by another machining ,

In a method according to the invention for producing a drawing shaft or a drawing roller, the outer surface of the outer connecting means of the drawing shaft or the inner surface of the inner connecting means of the drawing roller is produced by grinding, in the case of the drawing shaft in particular by external cylindrical grinding and in the case of the drawing roller in particular by internal cylindrical grinding. Similarly, milling, preferably fine milling, or turning, preferably fine turning, as a manufacturing process is possible.

The invention also provides a combination of a drawing shaft according to the invention and a drawing roller according to the invention, wherein the above-defined cross-sectional areas of the inner connecting means of the pulling shaft and the outer connecting means of the drawing roller to deviations, which serve to establish a fit between the outer connecting means and the inner connecting means, are essentially the same.

The fit is preferably chosen so that the two connecting means on the one hand have so much game that the pulling shaft can be inserted without effort and without the risk of damage in the drawing roller, and that the two connecting means on the other hand have so little game that the connection is sufficiently strong and transmits the drive torque safely.

Further advantageous embodiments of the invention will be explained in the accompanying drawings in conjunction with the following description. Showing:

1 a drawing shaft according to the invention and a drawing roller according to the invention in a perspective oblique view;

2 a cross section of the outer profile of a drawing shaft according to the invention and the inner profile of a drawing roller according to the invention.

1 shows a drawing shaft according to the invention 1 and a drawing roller according to the invention 2 , here for example for use in a multi-wire drawing machine.

The drawing roller 2 has on its outer surface a total of 16 circular grooves 5 on, in each groove 5 a portion of the wire to be pulled (not shown) can be inserted. In this way, the wire sections can not move axially and adjacent wire sections do not touch or damage each other.

The drawing roller 2 is preferably formed in several parts and has, as in 1 illustrated, a roller body and one or more separate sleeves with the grooves 5 , Preferably in the form of one or more ceramic sleeves, which is pushed onto the roller body and by a screwed lid 8th are secured. The drawing roller 2 However, it may also be formed in one piece and preferably consist of a single ceramic body.

The drawing roller 2 is intended to be on the right, cylindrical section 7 the pull shaft 1 to be deferred so that the axis of rotation 13 the pull shaft 1 and the rotation axis 14 the drawing roller 2 coincide, and from the drawing wave 1 To be driven by means of positive connection means. For this purpose, the drawing roller 2 an axial bore 6 on, which at the right end by a taper and the lid screwed into it 8th is limited. The pulling wave 1 stands in the mounted state thus only on the left side on the drawing roller 2 addition, whereby the threading of the wire sections during the commissioning of the drawing machine is facilitated.

The pulling wave 1 is in turn by a mounted on its surface, preferably with the pulling shaft 1 integrally formed gear 15 around its axis of rotation 13 driven in rotation.

The torque transmission from the pull shaft 1 on the drawing roller 2 takes place from an external connection means 3 on the drawing shaft 1 with a cross-sectional area 11 ( 2 ), whose edge is the outer profile 9 of the external connection means 3 forms, on an inner lanyard 4 in the hole 6 the drawing roller 2 wherein the one of the inner connecting means 4 surrounded space a cross-sectional area 12 whose edge has the inner profile 10 of the inner connecting means 4 forms. The external connection means 3 and the inner connecting means 4 come after sliding the drawing roller 2 on the drawing shaft 1 to be axially within the same range.

In 2 are the pulling wave 1 (left) and the drawing roller 2 (right) in the area of the outer lanyard 3 or the internal connection means 4 shown in cross section. The profiles 9 . 10 are approximately equal, with the inner profile 10 is preferably dimensioned slightly larger than the outer profile 9 , The inner profile 10 but can also be dimensioned slightly smaller than the outer profile 9 , Finally, the two profiles 9 . 10 be the same size. In this way, optionally, a clearance fit, a press fit or a transition fit between the pull shaft 1 and the drawing roller 2 possible.

Both profiles 9 . 10 have approximately the shape of a square with outwardly curved side edges and rounded corners.

The diameter of the smallest the profile 9 circumscribing circle is using d1 and the diameter of the largest the profile 9 Inscribed circle designated d2. Accordingly, the diameter of the smallest becomes the profile 10 circumscribing circle with d3 and the diameter of the largest the profile 10 inscribed circle denoted by d4. The ratio d1 / d2 and d3 / d4 is about 1.1 each. The largest diameter of the respective profile 9 . 10 So each is about 10% larger than its smallest diameter. In this way, the wall thickness of the drawing roller 2 and thus the stability of the drawing roller 2 at the points of largest diameter of the profile 10 (in 2 top, bottom, left and right).

LIST OF REFERENCE NUMBERS

1

pulling shaft

2

pull roll

3

Outer lanyard

4

Inner lanyard

5

groove

6

Axial hole in the drawing roller

7

Cylindrical section of the pulling shaft

8th

cover

9

Outer profile

10

Inner profile

11

Cross sectional area of the external connection means

12

Cross-sectional area of the space surrounded by the inner connecting means

13

Rotation axis of the drawing shaft

14

Rotation axis of the drawing roller

15

gear

d1

Diameter of the smallest circle circumscribing the outer profile

d2

Diameter of the largest circle inscribed in the outer profile

d3

Diameter of the smallest circle circumscribing the inner profile

d4

Diameter of the largest circle inscribed in the inner profile

Claims (13)

Pull shaft ( 1 ) with an external connection means ( 3 ) for producing a positive connection with an axial bore ( 6 ) and an inner, in the axial bore ( 6 ) arranged connecting means ( 4 ) having a drawing roller ( 2 ), wherein the positive connection is given when the axis of rotation ( 13 ) of the pulling shaft ( 1 ) and the axis of rotation ( 14 ) of the drawing roller ( 2 ) and the external connection means ( 3 ) of the pulling shaft ( 1 ) in the inner connecting means ( 4 ) of the drawing roller ( 2 ), characterized in that the external connection means ( 3 ) of the pulling shaft ( 1 ) at least one point a convex, non-circular cross-sectional area ( 11 ) perpendicular to the axis of rotation ( 13 ) of the pulling shaft ( 1 ) having. Pull shaft ( 1 ) according to claim 1, characterized in that the cross-sectional area ( 11 ) is rotationally symmetrical, in particular that the cross-sectional area ( 11 ) has a three, four, five or sixfold or an n-fold (with n greater than 6) rotational symmetry. Pull shaft ( 1 ) according to one of the preceding claims, characterized in that the Circumference line ( 9 ) of the cross-sectional area ( 11 ) has no kinks. Pull shaft ( 1 ) according to one of the preceding claims, characterized in that the cross-sectional area ( 11 ) has the shape of a square with outwardly curved side edges and with convex curves in the transition region of the side edges, in particular with rounded corners. Pull shaft ( 1 ) according to one of the preceding claims, characterized in that the ratio of the diameter (d1) of the smallest circle with the center on the axis of rotation ( 13 ) of the pulling shaft ( 1 ), which determines the cross-sectional area ( 11 ) to the diameter (d2) of the largest circle centered on the axis of rotation ( 13 ) of the pulling shaft ( 1 ), which in the cross-sectional area ( 11 ) is less than or equal to 1.25; preferably less than or equal to 1.2; more preferably less than or equal to 1.15; even more preferably less than or equal to 1.1. Method for producing a drawing shaft ( 1 ) according to one of the preceding claims, characterized in that the outer surface of the outer connecting means ( 3 ) is produced by grinding, milling, fine milling, turning or fine turning. Drawing roller ( 2 ) with an axial bore ( 6 ) and an inner, in the axial bore ( 6 ) arranged connecting means ( 4 ) for producing a positive connection with an external connection means ( 3 ) having a pulling shaft ( 1 ), wherein the positive connection is given when the axis of rotation ( 13 ) of the pulling shaft ( 1 ) and the axis of rotation ( 14 ) of the drawing roller ( 2 ) and the external connection means ( 3 ) of the pulling shaft ( 1 ) in the inner connecting means ( 4 ) of the drawing roller ( 2 ), characterized in that that of the inner connecting means ( 4 ) surrounded space in the axial bore ( 6 ) of the drawing roller ( 2 ) at least one point a convex, non-circular cross-sectional area ( 12 ) perpendicular to the axis of rotation ( 14 ) of the drawing roller ( 2 ) having. Drawing roller ( 2 ) according to claim 7, characterized in that the cross-sectional area ( 12 ) is rotationally symmetrical, in particular that the cross-sectional area ( 12 ) has a three, four, five or sixfold or an n-fold (with n greater than 6) rotational symmetry. Drawing roller ( 2 ) according to claim 7 or 8, characterized in that the peripheral line ( 10 ) of the cross-sectional area ( 12 ) has no kinks. Drawing roller ( 2 ) according to one of claims 7 to 9, characterized in that the cross-sectional area ( 12 ) has the shape of a square with outwardly curved side edges and with convex curves in the transition region of the side edges, in particular with rounded corners. Drawing roller ( 2 ) according to one of claims 7 to 10, characterized in that the ratio of the diameter (d3) of the smallest circle with center on the axis of rotation ( 14 ) of the drawing roller ( 2 ), which determines the cross-sectional area ( 12 ) to the diameter (d4) of the largest circle centered on the axis of rotation ( 14 ) of the drawing roller ( 2 ), which in the cross-sectional area ( 12 ) is less than or equal to 1.25; preferably less than or equal to 1.2; more preferably less than or equal to 1.15; even more preferably less than or equal to 1.1. Method for producing a drawing roller ( 2 ) according to one of claims 7 to 11, characterized in that the inner surface of the inner connecting means ( 4 ) is produced by grinding, milling, fine milling, turning or fine turning. Combination of a pulling wave ( 1 ) according to one of claims 1 to 5 and a drawing roller ( 2 ) according to one of claims 7 to 11, characterized in that the convex, non-circular cross-sectional area ( 11 ) of the external connection means ( 3 ) of the pulling shaft ( 1 ) perpendicular to the axis of rotation ( 13 ) of the pulling shaft ( 1 ) and the convex, non-circular cross-sectional area ( 12 ) of the inner connecting means ( 4 ) surrounded space in the axial bore ( 6 ) of the drawing roller ( 2 ) perpendicular to the axis of rotation ( 14 ) of the drawing roller ( 2 ) except for variations in the production of a fit between the external connection means ( 3 ) and the inner connecting means ( 4 ) are essentially the same.

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