EP3060359B2 - Roller burnishing tool - Google Patents

Description

The invention relates to a burnishing tool for producing a toothed structure in the wall of a preform. In general, this involves the production of splines in the wall of a cylindrical blank in order to produce a gear wheel.

Such a roller burnishing tool comprises disc-like rollers that are rotatably mounted. The rollers are arranged such that their peripheral edges roll along the lateral surface of the cylindrical blank while exerting a pressure on the lateral surface so that the lateral surface is indented, forming a tooth gap. A variety of roles are associated with the preform. The roles run - viewed in plan view of the cylindrical blank - more or less radially to this. At the same time, a so-called stamp is provided inside the blank. This fills the interior of the blank. The stamp is toothed in the manner of a gear wheel, so that when a tooth gap is created by one of the disc-shaped rollers mentioned, a tooth of the stamp presses from the inside onto the wall of the cylindrical blank, thereby pushing material between two adjacent rollers outwards and thus forming a tooth on the blank .

on EP 2 282 854 B1 reference is made which describes a roll forming process.

With roller burnishing tools of the type described, the aim is to produce an end product that will maintain the specified dimensions with a high level of accuracy. This applies in particular to the width of the tooth gaps. However, it has been shown again and again that this requirement cannot be met. Deviations from the target dimension are primarily due to differences in the quality of the steel used. This can lead to significant deviations from the target dimensions when using qualitatively different steel batches.

In the event of such deviations, changes must be made to the roller burnishing tool. In particular, it is then necessary to replace the disk-shaped rollers. If the roller burnishing process leads to excessively deep tooth gaps, then rollers with a small diameter must be selected, and vice versa. Such change processes are time-consuming and expensive. In particular, a large stock of burnishing rollers is required. If there are dimensional deviations in the workpiece, the current rollers must be removed from the roller burnishing tool, suitable roller rollers selected from stock and installed.

DE 2 017 709 describes a tool for rolling longitudinal grooves into cylindrical workpieces, the profile rollers being movably mounted in the direction of the rolling force. Each profile roller is supported by two support rollers which touch the profile roller on their circumference and are mounted in a receiving body. An adjustment wedge is provided between each receiving body and an inner wall of a reinforcement ring, which can be adjusted by two tension screws. The disadvantage of this arrangement is that the profile rollers can only be replaced, for example by a roller with a new outer contour to produce a different type of toothing, with a simultaneous adjustment, in particular an exchange of the support rollers, and the entire arrangement requires a large amount of space and an unfavorable load introduction into the various components.

DE 10 2009 044 544 A1 describes a forming device and a setup method for introducing internal and external teeth into a cylindrical workpiece, in which the profile rollers are mounted on eccentric bushes for adjustment. For further prior art is on DE 10 2008 017 608 B3 and DE 10 2007 062 361 A1 referred.

EP 0 761 338 A1 discloses a burnishing tool for producing a tooth structure in a wall of a cylindrical blank, with a wedge-shaped intermediate body being provided, and with radial forces arising being absorbed exclusively by abutments that radially support the rollers, but not by a cage that holds the profile rollers in a common plane. The shafts or bolts used to support the rollers are essentially force-free.

The invention is based on the object of designing a burnishing tool in accordance with the preamble of claim 1 in such a way that one can react quickly and with little effort to dimensional deviations of the workpiece. In particular, the roller burnishing tool is intended to provide an alternative to the conventional adaptation of the penetration depth or the profile of the rollers that is improved in terms of installation space and costs as well as in terms of service life.

This task is solved with a burnishing tool of each of the three independent patent claims.

An intermediate body is advantageously provided for all three main ideas. This exerts pressure on the bearing journals of the rollers so that they are pushed against the outer surface of the blank. Each intermediate body is supported on a fixed environment.

According to the first main idea, the intermediate body is wedge-shaped. The contact pressure can be adjusted by adjusting the position of the wedge-shaped intermediate body. The position of the intermediate body in a feed direction for generating a relative movement between the rollers and the blank is determined by at least one exchangeable spacer.

For example, the at least one spacer is formed by at least one exchangeable positioning ring or an exchangeable positioning ring segment, generally a multiplicity of positioning ring segments arranged distributed over the circumference. For example, the wedge-shaped intermediate body in the feed direction mentioned for generating the relative movement can be enclosed on both sides by exchangeable spacers, in particular by exchangeable positioning rings or exchangeable positioning ring segments. In particular, the wedge-shaped intermediate body, which is advantageously designed as a wedge ring, rests on at least one spacer element, advantageously at least one positioning ring or a large number of positioning ring segments, and is carried by it.

The spacer, in particular the at least one positioning ring or the positioning ring segments, can be detachably connected, in particular screwed, to the intermediate body.

According to the second main idea of the invention, an intermediate body is provided which includes a hydrostatic pressure chamber. By changing the hydrostatic pressure, the position of the rollers relative to the blank can be changed. The hydrostatic chamber can be connected to a hydrostatic pressure medium in order to inflate said chamber to a greater or lesser extent and thus change the dimensions of the intermediate body in the pressing direction.

According to the third main idea of the invention, the temperature of the intermediate body or another element that exerts the contact pressure at least indirectly can be controlled, preferably by means of electrical resistance heating. This also allows the distance between the rollers to be changed relative to the blank.

Particularly in the case of the second and third main idea of the invention, the position of the rollers relative to the blank can be changed advantageously during operation, at least without any modification or removal of the rollers.

Figur 1

zeigt in einem Axialschnitt die wesentlichen Bauteile eines Rollierwerkzeugs gemäß einem Ausführungsbeispiels der Erfindung.

Figur 2

zeigt in perspektivischer Darstellung einen Ausschnitt aus dem Rollierwerkzeug gemäß Figur 1.

Figur 3

zeigt wiederum in einer perspektivischen Darstellung einen weiteren Ausschnitt aus dem Gegenstand von Figur 1.

The invention is explained in more detail with reference to the figures and an exemplary embodiment. It details the following:

figure 1

shows in an axial section the essential components of a burnishing tool according to an embodiment of the invention.

figure 2

shows a perspective view of a section of the roller burnishing tool according to FIG figure 1 .

figure 3

shows again in a perspective view a further detail from the subject of figure 1 .

This in figure 1 The roller burnishing tool shown comprises the following components: One of numerous rollers 1 (roller rollers) is rotatably mounted on a bearing pin 2 . The bearing pin 2 is in turn mounted in a housing 3. The housing 3 is fixed in a so-called boiler house 4, which has a cover 5.

A blank 6 has the shape of a cylindrical hollow body with a closed bottom 6.1 and a cylindrical wall 6.2. The blank 6 is made from a blank by deep drawing. The circuit board is a circular steel disk. In order to produce a gear from the blank 6, grooves must be pressed into the wall 6.2 by rolling using the rollers 1. In the present case, this occurs in that the blank 6 is shifted from an upper position I, shown here, into a lower position II, also shown. As can be seen, the roller 1 is mounted and arranged in such a way that when the blank 6 is lowered, it presses its wall 6.2 inwards. Two adjacent rollers 1 each form a tooth that runs parallel to the feed direction 7 of the blank 6 .

The blank 6 is clamped between a counter-holder 8 and a punch 9. The counter-holder 8 is firmly connected to a sleeve 10, for example by screwing. The stamp 9 is located within the blank 6. It is itself designed like a gear. The teeth of the stamp 9 work together with the rollers 1 during the burnishing process, in that one tooth of the stamp 9 engages between two rollers 1 that are adjacent to one another.

According to the first main idea of the invention, an intermediate body 11 is provided. This is preferably designed as a wedge ring and encloses all the rollers 1 with the plurality of housings 3 and the blank 6 arranged in the center figure 2 apparent. The intermediate body 11 can be divided into numerous individual bodies or can be made in one piece.

The radial position of the rollers 1 can be adjusted by means of the wedge-shaped intermediate body 11. how to get out figure 1 recognizes, this is located in a likewise annular and wedge-shaped receiving space 12. The further the wedge-shaped intermediate body 11 is driven into the receiving space 12, the deeper the peripheral edge of the individual roller 1 penetrates into the material of the blank 6 and the greater the tooth height .

From the figures 2 and 3 one recognizes more precisely the shape and arrangement of the rollers 1 and the associated housing 3. Two adjacent rollers 1 are arranged in a housing 3, here in two parts. A wedge segment 15 is located between two adjacent pairs of rollers 1. This is stationary and determines the orientation and position of the housing 3, and thus also of the rollers 1.

In the present exemplary embodiment, the boiler house 4 with the housings 3 and rollers 1 arranged therein is stationary. On the other hand, the preform 6 performs the already mentioned translational movement in the feed direction 7, here from top to bottom, optionally also from bottom to top. During its translational movement, the blank 6 takes the rollers 1 with it by means of frictional engagement and thus causes them to rotate. The rollers 1 therefore do not need their own drive.

The position of the intermediate body 11 in the feed direction 7 is defined by interchangeable positioning rings 14. The positioning rings 14 can be designed as rings that are closed over the circumference. However, they can also be formed by a multiplicity of individual ring segments positioned at a distance from one another or adjacent to one another. Finally, instead of the positioning rings 14, non-annular spacers can also be used. The spacers, here the positioning rings 14, define the penetration depth of the disc-shaped rollers 1 into the material of the blank 6 with the position of the intermediate body 11 in the feed direction 7 at the same time. The penetration depth can thus be changed by inserting positioning rings 14 of a thickness (height) designed accordingly. If the positioning ring 14 is comparatively thinner in the feed direction 7 at the narrower end of the receiving space 12, the wedge-shaped intermediate body 11 penetrates deeper into the tapering receiving space 12 and pushes the housing 3 resting against it and thus the roller 1 via the bearing journal 2 comparatively further in the direction of the blank 6. If, on the other hand, a comparatively thicker positioning ring 14 is inserted here (in the drawing below in the receiving space 12), the intermediate body 11 in Shifted towards the further section of the receiving space 12, so that the housing 3 with the roller 1 can press further in the direction of the supporting fixed environment, here the boiler house 4, and the roller 1 dips less into the wall 6.2 of the blank 6.

In the exemplary embodiment shown, the bearing journals 2 have a special shape, which can also be designed independently of the features further described in this exemplary embodiment. Thus, the bearing journals 2, each of which carries a roller 1, here a pair of rollers 1, are provided with a flattening 13 on their axial sections which protrude beyond the rollers 1 and are inserted into the housing 3 or the housings 3. This flattening 13 is in the figures 1 , 2 and 3 evident. The flats 13 are provided on the peripheral portion of the bearing journals 2 positioned towards the fixed environment on which the housings 3 are supported via the intermediate body or bodies 11 . This achieves a more favorable surface pressure between the bearing journals 2 and the housings 3 when the compressive force resulting from the advancement of the rollers 6 in the feed direction 7 is transmitted via the rollers 1, the bearing journals 2, the housing 3, the intermediate body or bodies 11 into the fixed environment, here boiler house 4. A flattening 13 can, for example, as shown in FIG figure 2 as can be seen, transition into the round, in particular circular, peripheral region of the bearing journal 2 via a bevel or a chamfer in the circumferential direction. The counter-contour in the housing 3 does not have to be designed identically; for example, a round or rounded transition in the circumferential direction from the area of the flattening to the round or circular circumferential section is possible there.

In the design shown here, the bearing journals, which are essentially cylindrical with the exception of the flat areas 13, are provided with beveled end faces, see bevel 16. The two end bevels 16 of a bearing journal 2 run towards one another in the direction of the blank 6. As a result, the bearing journals 2 can be positioned closer to one another in the manner of a polygon over the circumference of the blank 6 . Advantageously, the housing 3 accommodating the bearing journals 2 has a corresponding bevel 17 on the sides facing away from the rollers 1 it carries, which in particular ends flush with the bevel 16 of the bearing journals 2 and/or is positioned plane-parallel thereto.

In the exemplary embodiment shown, the housings 3 also have a flat contact surface on their outer side facing the intermediate body 11, in contrast to an annular contact surface. This also leads to a more favorable surface pressure. The one or more intermediate bodies 11 accordingly have flat contact surfaces on their inner circumference, which faces the blank 6, and form, as can be seen from FIG figure 3 is particularly clearly visible, a polygon on its inner circumference. On the other hand, the outer circumference of the intermediate body or bodies 11 can be annular, although this is not mandatory, depending on the design of the contact surface of the fixed environment, here the boiler house 4.

The rollers 1 are mounted exclusively on the bearing pins 2, so no support rollers or the like are provided or support areas on the outer circumference of the rollers 1. It is therefore particularly easy to use a roller 1 with a first outer contour, which forms a first type of toothing. to be replaced by another roller 1 with a different contour for a different type of toothing. In the present case it is also easily possible due to the design of the housing 3 to remove it together with the rollers 1 from the areas between the wedge segments 15 . Thus, two housings 3 or housing parts are always angular, in particular L-shaped, and form a U-shape when assembled, in which a roller 1 or, in this case, a pair of rollers 1 is accommodated. At the outer end, the legs of the L-shaped housing parts abut one another and at the inner end, the distance is defined and secured by the bearing pins 2 used.

In the bearing journal 2, a lubricating oil groove 18 can be introduced, which here in the figure 2 can be seen and is present on top of the bearing pin 2 is carried out.

The paired use of rollers 1 shown here, with two sets 1 being inserted adjacent to one another in a housing 3 formed from two parts or in two adjacent housings 3, offers the advantage that rollers 1 that are comparatively small in diameter are used can without the risk of a collision of the components supporting them over the circumference of the blank 6 looming. A particularly compact embodiment can thus be created.

In the exemplary embodiment shown here, two spacers are provided, preferably in the form of positioning rings 14 or two groups of spacers or positioning ring segments, namely a spacer or a first group below the intermediate body or bodies 11 and a second spacer or a second group above the one or the Intermediate bodies 11. These two spacers or groups of spacers together form a constant height, so that an exchange of the intermediate body or bodies 11 for setting different penetration depths of the rollers 1 into the blank 6 is not necessary. If the intermediate body or bodies 11 were to be fastened in another way, however, a spacer or a group of spacers could possibly be dispensed with.

Here the spacers (positioning rings 14) are screwed to the intermediate body 11. This is particularly advantageous when a large number of spacers are used over the circumference of an intermediate body 11 or a large number of intermediate bodies 11 are used over the circumference of the blank 6 . However, it is possible to dispense with such a screw connection or to use another form-fitting and/or friction-fitting, but generally detachable connection.

The other two main ideas are also very interesting in practice. This allows the dimension of the intermediate body (or a plurality of intermediate bodies) 11 to be changed in the pressing direction of the rollers 1 . In the case of the second main idea, this happens by means of hydrostatic pressure. Intermediate body 11 can namely have a space which can be connected to a hydrostatic pressure medium, for example to a pressure oil, and which can inflate said space and thus increase the dimensions of intermediate body 11 in the pressing direction.

According to the third main idea, the contact pressure that acts on the bearing pin 2 and thus on the penetration depth of the roller 1 into the wall 6.2 of the blank 6 is generated by tempering, preferably by means of electrical resistance heating. Whether you use an intermediate body or another element that is responsible for the contact pressure is a secondary question.

The invention can be used not only in the production of spur gears, but also in helical gears. It does not even have to be gear wheels, but any gearing can be considered for the application of the invention, even on non-rotating components.

reference list

1

role

2

bearing journal

3

Housing

4

boiler house

5

lid

6

blank

6.1

floor

6.2

Wall

7

feed direction

8th

counter holder

9

Rubber stamp

10

quill

11

intermediate body

12

recording room

13

flattening

14

positioning ring

15

wedge segment

16

bevel

17

bevel

18

lubricating oil groove

Claims (13)

1. Roller burnishing tool for producing a toothed structure in a wall (6.2) of a cylindrical blank (6), comprising the following features:

   1.1 a clamping device for retaining the blank (6);

   1.2 a rim of disk-shaped rotatably mounted rolls (1) whose peripheral edges are directed against the wall (6.2) of the blank and are adapted to be pressed there against;

   1.3 bearing pivots (2) for bearing the rolls (1);

   1.4 a stamp (9) in the interior of the blank (6) with a toothed structure as a counter mold;

   1.5 a drive for generating a relative movement in a feed direction (7) between the rolls (1) and the blank (6);
   characterized by the following features:

   1.6 a wedge-shaped intermediate body (11) is provided which presses the rolls (1) by exerting a pressure on the bearing pivots (2), supports itself at a fixed environment, and whose position in the feed direction (7) is determined by at least one exchangeable spacer.
2. A roller burnishing tool for producing a toothed structure in a wall (6.2) of a cylindrical blank (6), comprising the following features:

   2.1 a clamping device for retaining the blank (6);

   2.2 a rim of disk-shaped rotatably mounted rolls (1) whose peripheral edges are directed against the wall (6.2) of the blank and are adapted to be pressed there against;

   2.3 bearing pivots (2) for bearing the rolls (1);

   2.4 a stamp (9) in the interior of the blank (6) with a toothed structure as a counter mold;

   2.5 a drive for generating a relative movement between the rolls (1) and the blank (6);
   characterized by the following feature:

   2.6 an intermediate body comprising a hydrostatic chamber for positioning the rolls (1) relative to the blank (6) is provided,

   wherein the hydrostatic chamber is connectable to a hydrostatic pressure medium to inflate the hydrostatic chamber and thereby change the dimension of the intermediate body in a pressing direction,

   wherein the intermediate body exerts a pressure on the bearing pivots (2) of the rolls so that these are displaced against the circumferential surface of the blank (6) and supports itself at a fixed environment.
3. A roller burnishing tool for producing a toothed structure in a wall (6.2) of a cylindrical blank (6), comprising the following features:

   3.1 a clamping device for retaining the blank (6);

   3.2 a rim of disk-shaped rotatably mounted rolls (1) whose peripheral edges are directed against the wall (6.2) of the blank and are adapted to be pressed there against;

   3.3 bearing pivots (2) for bearing the rolls (1);

   3.4 a stamp (9) in the interior of the blank (6) with a toothed structure as a counter mold;

   3.5 a drive for generating a relative movement between the rolls (1) and the blank (6);
   characterized by the following features:

   3.6 a tempering device, especially an electrical resistance heating, is provided to adjust the position of the rolls (1) relative to the blank (6), namely by tempering a component carrying the rolls (1) directly or indirectly.
4. The roller burnishing device according to claim 1, characterized in that the at least one spacer is formed by at least one exchangeable positioning ring (4) or exchangeable positioning ring segments.
5. The roller burnishing device according to claim 4, characterized in that the wedge-shaped intermediate body (11) is enclosed in the feed direction (7) on both sides by exchangeable spacers, especially positioning rings (14) or positioning ring segments.
6. The roller burnishing device according to any of claims 4 or 5, characterized in that the wedge-shaped intermediate body (11) rests on and is carried by at least one spacer, especially positioning ring (14), or a plurality of positioning ring segments.
7. The roller burnishing device according to any of claims 4 to 6, characterized in that the spacer, especially the at least one positioning ring (14) or the positioning ring segments, is/are connected releasably with the intermediate body (11), in particular screwed on.
8. The roller burnishing device according to any of claims 1 to 7, characterized in that the intermediate body (11) is designed as a tapered ring.
9. The roller burnishing device according to any or several of claims 1 to 8, characterized in that the rolls (1) are stored in a boiler house.
10. The roller burnishing device according to any of claims 1 to 9, characterized in that one roll or a pair of rolls (1) is each disposed in a single-part or multi-part, in particular two-part housing (3) and is carried by means of a bearing pivot (2) mounted in the housing (3).
11. The roller burnishing device according to any of claims 1 to 10, characterized in that the rolls (1) are positioned on bearing pivots and are carried thereby, wherein the rolls (1) are especially mounted exclusively by the bearing pivots (2).
12. The roller burnishing device according to any of claims 10 or 11, characterized in that the bearing pivots (2) comprise, at the two axial ends thereof, a bevel (16) over the circumference through which the pressure force acting on the rolls (1) is dissipated into the housings (3).
13. The roller burnishing device according to any of claims 1 to 12, characterized in that the bearing pivots (2) are, on both of their front sides, provided with bevels (17) approaching each other and are positioned over the circumference of the blank (6) like a polygon.

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