EP1163961B1 - Method and apparatus for manufacturing a gearing element - Google Patents

Abstract

The part is formed from a round blank, which is clamped in a tool and reduced in thickness by a pressure roller moving in a radial direction. The blank is clamped by pressing an edge section axially against the tool and simultaneous radial expansion of the blank against a ring-shaped axially projecting part of the tool. The blank is held non-positively and/or positively on the tool, by esp. a magnetic or vacuum clamping device until the clamping force is generated.

Description

The invention relates on the one hand to a method for the production a gear part with a hub from a round blank, which on a tool of a rotating drivable spindle Pressing machine is arranged and clamped and by means of at least one pressure roller reduces the thickness of the round blank and the resulting material is transformed into a hub becomes.

On the other hand, the invention relates to a pushing device with a rotating drivable spindle, at least one adjustable spinning roller and one attached to the spindle Tool for holding a round blank.

A generic method and a generic device can be seen, for example, from DE-C-198 49 981. In this known pressing method, the blank is against an annular tool by means of a cylindrical one Pressing element pressed. With this simple and reliable axial clamping can be an outer area of a Ronde can be processed very well. With this axial clamping can, however, be within the trainee Do not avoid a certain radial disc area, which may be in a later step must be removed. A device with a separate Abutment chuck is further apparent from DE-C-44 44 526. The abutment chuck that works with the tool can be placed on the circumferential edge of the round blank.

It is a step further when molding a hub onto a sheet metal blank known, this by so-called lathe chucks on its outer circumference clamped on a tool. The lathe chuck points three or four radially adjustable jaws, between which the circular workpiece is clamped can. However, such tensioners are relative complex and sometimes hinder the editing of Round plate using spinning rollers. For relatively thin workpieces can not be sufficient to a correspondingly thin peripheral edge Clamping range for reliable clamping of the Workpiece.

A method is known from EP-A-0 815 983 and US-A-5,987,952 known in which a circular blank is inserted into a receptacle and is axially clamped by means of a central pressure element. A holding roller holds the while the hub is being formed outer edge of the blank in the picture. The holding roll hinders free access to the center of the round blank.

The invention is based on the object of specifying a method and a device with which simple and reliable holding of the workpiece on the tool is provided, at the same time ensuring a high degree of design freedom when forming the hub.

The task is accomplished on the one hand by a procedure with the Features of claim 1 solved. On the other hand, the task is performed by a device with the features of claim 10 solved.

The method according to the invention is characterized in that that the circular blank is clamped by axial pressure of a blank area of the blank against the tool and simultaneously expanding the circular blank radially and that when expanding the circular blank radially this against an annular circumferential direction Wall is formed on the tool, the round blank non-positively and / or positively held on the tool becomes.

A basic idea of the invention is the tool to be provided with an annular wall, which only slightly is larger than the blank used in it. The Ronde is then replaced by a axial contact force radially expanded and thus against the annular wall either radially outwards or radially shaped inside. This results in a force and / or positive connection between the blank and the tool. The blank is then clamped to the tool through an interaction between the formed blank and the surrounding annular wall or a central centering pin reached on the tool. The device can thus be trained easily and inexpensively, the whole Area of the circular blank machined free from the spinning roller can be. It is a particularly high degree of design freedom given for machining the round blank and for the hub. The with the exception of the pressure element basically be constructed as in the the applicant declining DE 198 49 981 C1 is described.

In a preferred embodiment of the invention, the circumferential wall of an annular Paragraph formed with respect to the face of the tool, against which the circular blank is pressed when expanding radially protrudes axially. The ring-shaped heel can be this embodiment directly on the front of the Be trained tool. Alternatively, it is also possible the circumferential edge of the face of the tool with a chamfer to be provided, which in turn in the axially preceding paragraph transforms. Through such a design of the paragraph can the outer edge region of the round blank in the axial direction be reshaped, the bevel angle being the bend angle of the edge area of the circular blank. This results in the advantage that the blank is special after spinning easy, d. H. detached from the tool with little effort can be. The shoulder is dimensioned in the axial direction so that it is preferably over the face of the tool survives.

Furthermore, it is proposed at the front of the Tool against which the circular blank is pressed during radial expansion will form a circumferential groove, one of which annular groove wall at least partially in the circumferential direction trending wall forms. The round plate is used to hold its edge area into the groove on the flat tool surface molded in such a way that the blank is non-positive and / or positive is held on the groove wall. In this embodiment it is also conceivable, likewise those previously described Provide paragraph on the tool, the paragraph with its wall running in the circumferential direction Merges into the annular groove wall on the inside.

A preferred development of the invention consists in that reducing the thickness of the blank by radial feeding a spinning roller, the spinning roller at the same time the blank with a defined axial force presses axially against the tool. In addition to a radial force component the spinning roller thus also has an axial force component on which a non-rotatable connection between the blank and the tool supported.

A particularly reliable process sequence is the subject of the invention in that until the generation of the Force and / or form-fit the blank using a separate Holding device, in particular a magnetic clamping device or a vacuum chuck on the tool is held. By arranging a controllable Electromagnetic coil on the tool or the arrangement of Vacuum channels on the tool open to the workpiece, which are a vacuum generator connected to the line the round blank can be inserted into the ring Tool can be fixed. The final clamping takes place then according to the invention by pressing the pressure roller and reshaping the edge area of the circular blank in an axial Undercut area and / or radial driver element on the ring-shaped wall of the tool.

If no separate holding device is used, it is it makes sense that the blank placed on the tool at still stationary spindle axially with the at least one Pressure roller is pressed against the tool. Only in this pressed position, the spindle together with the Tool and the blank are set in rotation, whereby the pressure roller due to the frictional contact rotates with the blank and this reliably to the Tool presses.

Furthermore, in a preferred embodiment of the Proposed procedure, at least during the Form the hub axially with the help of a pressure element to press the tool, the pressing element Support hub material when molding the hub. The pressing element is designed so that the outer contour of the pressing element has an area that corresponds to an area the inner contour of the hub to be formed corresponds. The pressing element is used in this embodiment So as a tool mandrel, with the help of the inner contour of the This is how the hub is preformed while the hub is being shaped is that at most a comparatively minor Reworking the hub is required.

In an alternative embodiment of the method proposed to expand the blank even before radial expansion with the help of a pressure element axially to the tool press, the pressing element with one from the front protruding pin of the tool engages, through a receiving opening formed on the round blank protrudes. After the radial expansion to hold the blank on The pressing element is moved away by the tool. In this way can the pin provided on the tool the hub material support when shaping the hub, similar to the previous one described embodiment, the outer contour of the pin has an area that corresponds to an area of the inner contour corresponds to the hub to be formed, so that here too at best a slight reworking of the hub a later date is required. With regard to the device, the object is achieved according to the invention solved by the fact that an annular, in Circumferential direction wall is formed on the the blank by radial expansion non-positively and / or positively is mountable, and that an ejector device is provided. The ring-shaped wall of the tool points an inner diameter which is slightly larger than the outer diameter of the round blank is such that an almost backlash-free insertion of the blank is granted. Through this annular wall will position the exact location Ronde reached on the spindle, being by radial expansion the blank is a non-positive and / or positive, non-rotatable connection of the circular blank with the tool and thus can be generated with the spindle. It is therefore simple A firm and at the same time precise positioning of one given a circular workpiece, with a free machining the entire round surface on one round side is possible. The ejector device, which in particular an axially movable stamp or a support element allows the round blank to be removed easily.

In a preferred embodiment of the invention Device the wall is formed on an annular shoulder, the axially with respect to the end face of the tool protrudes. It is also possible to on the front of the Tool form a circumferential groove, the one groove wall at least partially the one running in the circumferential direction Wall forms.

An even better connection between the round-shaped Workpiece and the tool on the spindle is invented achieved by facing towards the round blank Profiling of the circumferential side of the annular wall trained to produce a positive connection is. The profiling can be in an axial undercut or in the arrangement of radially directed driver elements formed along the inside of the annular wall his. The driver elements can have a toothing, in particular form spur gear teeth on the workpiece. The driver elements run in the axial direction trained that an ejector axially the workpiece can remove the tool.

Fig. 1

eine Schnittansicht eines ersten Ausführungsbeispieles einer Drückvorrichtung mit einer an der Stirnseite des Werkzeuges ausgebildeten Nut;

Fig. 2

eine Schnittansicht eines zweiten Ausführungsbeispieles einer Drückvorrichtung mit einer an der Stirnseite des Werkzeuges ausgebildeten Nut und einem an der Stirnseite vorgesehenen Zentrierzapfens beim Spannen der Ronde; und

Fig. 3

eine Schnittansicht des zweiten Ausführungsbeispieles nach Fig. 2 beim Ausformen der Nabe.

The invention is explained in more detail below on the basis of several exemplary embodiments with reference to the schematic drawing. In it show:

Fig. 1

a sectional view of a first embodiment of a pressing device with a groove formed on the end face of the tool;

Fig. 2

a sectional view of a second embodiment of a pressing device with a groove formed on the end face of the tool and a centering pin provided on the end face when tensioning the round blank; and

Fig. 3

a sectional view of the second embodiment of FIG. 2 when molding the hub.

Fig. 1 shows a sectional view of a first embodiment a pressing device 10 for producing a Gear part 12 with hub 14 from a blank 16. The pressing device 10 is in Fig. 1 in various stages of the process shown. So shows the left of the axis of rotation R of the pushing device 10 can be seen the Pushing device 10 when tensioning the blank 16. The right the view seen from the axis of rotation R shows the Pushing device 10 during the molding of the hub 14.

The pressing device 10 has a tool 18, which by means of a drive, not shown, about the axis of rotation R is rotatable. On the end face 20 of the tool 18 a groove 22 is formed concentrically to the axis of rotation R. A groove wall 24 with a greater radial distance from Rotation axis R runs at least approximately parallel to Axis of rotation R and forms a wall, the purpose of which later will be explained later. An inner groove wall 26 with less radial distance to the axis of rotation R goes under formation a curve in the end face 20. In the illustrated The embodiment is the outer groove wall 24 distance smoothly formed. Alternatively, it is also possible to use the outer groove wall 24 shaped elements such as teeth, grooves or similar form, to form fit with the one to be formed later Manufacture blank 16. In the same way, the Groove base of the groove 22 provided with corresponding shaped elements his.

The tool 18 is also concentric to the axis of rotation R a cylindrical ejector 28 is slidably received, with which the finished transmission part 12 after completion of the pressure rolling process can be released from the tool 18.

A center hole is also concentric to the axis of rotation R. 30 formed in the ejector 28, which is for receiving a centering pin 32 of a holding element 34 serves, as Fig. 1 shows. The holding element 34 has one adjoining the centering pin 32 supporting section 36 with a round cross-section, which in turn in a holding device 38 passes.

For shaping the hub 14, the pressing device 10 a spinning roller 40, which in a common rotation of the tool 18 with the holding element 34 radially in the direction is delivered to the center of the blank 16. The Press roller 40 has a cutting edge 42, the to the cutting edge 42 adjacent peripheral surfaces of the Pinch roller 40 at an acute angle. To the Cutting edge 42 is followed by a compression area 44 which in turn limited by a projection 46 of the spinning roller 40 is.

To form the gear part 12, the blank is first 16 attached to the end face 20 of the tool 18 and that axially movable holding element 34 against the end face 20 moved so that the centering pin 32 by one on the Ronde 16 trained receiving opening 48 is guided and enters the centering mold 30. The holding element 34 is thereby moved axially in the direction of the end face 20, that at the transition between the centering pin 32 and the Support portion 36 formed paragraph 50 on the front the blank 16 abuts and so the blank 16 against the tool 18 preloaded. Then the tool 18 and the holding element 34 is rotated and the spinning roller 40 delivered, whereby the circular blank 16 extends radially and molded into the groove 22 with its edge region becomes. In this way, the blank 16 is non-positively the end face 20 of the tool 18 clamped.

Thereafter, the pressure roller 40 becomes radial in the direction of the axis of rotation R moves, the cutting edge 40 with the Round 16 comes into engagement. By the radial delivery of the Press roller 40 is partially separated material from the blank 16 and guided along the compression area 44 so that starting from the round blank 16, a revolving, while of the delivery process always changing collar. The axial flow of material is through the projection 46 Press roller 40 limited. In this way, the hub 14 turns on the gear part 12 to be manufactured from the blank 16 is formed, the holding element 34 serves as a tool mandrel the transition between the centering pin 32 and the Support section 36, on which the hub 14 is formed, at least partly for shaping the later inner contour Inner contour of the hub 14 is used.

After the hub 14 is formed, the spinning roller 40 moved away from the forming point, the holding element 34 Move away from tool 18 and then the finished one Gear part 12 using ejector 28 from tool 18 solved. This will release the finished gear part 12 due to the curvature on the groove wall 26 with little radial Distance easier because of the edge area of the gear part 12 is also rounded at the bottom.

2 and 3 show a second embodiment a pushing device 60, which is essentially constructed the structure of the pressing device 10 of the first embodiment like. The pushing device 60 differentiates only compared to the pressing device 10 the ejector 62 used and the holding element used 64. In the pressing device 60 is from the front the ejector 62 axially from a centering pin 66, the arranged concentrically to the axis of rotation R of the tool 18 is. The holding element 64 also has a concentric centering opening formed to the axis of rotation R. 68 with which the centering pin 66 engages can be brought, as Figure 2 shows.

To form the gear part 12, the blank 16 is also its receiving opening 48 initially on the centering pin 66 placed. Then the holding element 64 is against the tool 18 moves, the centering opening 68 with the centering pin 66 comes into engagement. The holding element 64 is biased axially against the tool 18 so strongly that the blank 16 rotatably. with the tool 18 and the holding element 64 is connected. Then the tool 18 and the holding element 64 in rotation and how in the first embodiment, using the spinning roller 40 the blank 16 is initially expanded radially. Through the radial Widening the circular blank 18 is molded into the groove 22, so that there is a positive connection between the blank 16 and the tool 18 forms. Subsequently the holding element 64 is moved away from the tool 18 and shaped the round blank 16 with the aid of the pressure roller 40, 3 shows. The centering pin 66 is used here as a tool mandrel for the hub 14 to be formed appropriate design of the centering pin 66 can this way, a hub 14 can be formed, the one Has through hole with a constant diameter.

The exemplary embodiments described above show only different options, such as a pushing device can be designed in accordance with the invention. About that it is also within the scope of the invention that previously described pushing devices additionally with magnetic clamping device or vacuum clamping devices.

Claims (10)

1. Method for the manufacture of a gear part (12) with a boss (14) from a round blank (16), which is placed and clamped on a tool (18) of a spindle, drivable in rotary manner, of a spinning lathe (10; 60), by means of at least one spinning roller (40) a thickness of the round blank (16) is reduced and the material obtained is shaped into the boss (14), characterized in that the clamping of the round blank (16) is brought about by axially pressing a marginal area of said blank (16) against the tool (18) accompanied by a simultaneous radial expansion of the blank (16) and that on radially expanding the round blank (16) it is shaped against an annular, circumferentially directed wall (24) on the tool (18), the round blank (16) being secured in positive and/or frictional engagement on the tool.
2. Method according to claim 1, characterized in that the circumferentially directed wall passes completely round and is formed by an annular shoulder, which projects axially with respect to the end face of the tool, against which the round blank is pressed during radial expansion.
3. Method according to claim 1 or 2, characterized in that a circumferential groove (22), whose annular groove wall (22) at least partly forms the circumferentially directed wall, is constructed on the end face (20) of the tool (18), against which the round blank (16) is pressed during radial expansion.
4. Method according to claim 1, 2 or 3, characterized in that the reduction of the thickness of the round blank (16) is brought about by the radial infeeding of the spinning roller (14), which simultaneously presses the round blank (16) with a clearly defined axial force in axial manner against -the tool (18).
5. Method according to one of the claims 1 to 4, characterized in that until the positive and/or frictional engagement is produced, the round blank (16) is secured on the tool by means of a separate retaining device, particularly a magnetic clamping device or a vacuum clamping device.
6. Spinning device, particularly for performing the method according to one of the claims 1 to 5, having a spindle drivable in rotary manner, at least one infeedable spinning roller (40) and a tool (18) fitted to the spindle for securing a round blank (16), characterized in that on the tool (18) is formed an annular, circumferentially directed wall (24) on which the round blank (16) can be secured in positive and/or frictional engagement by radial expansion and that an ejector is provided on the tool.
7. Spinning device according to claim 6, characterized in that the circumferentially directed wall is formed by an annular shoulder, which projects axially with respect to the end face of the tool, on which the round blank at least partly engages during securing.
8. Spinning device according to claim 6 or 7, characterized in that a circumferential groove (22), whose one groove wall (24) at least partly forms the circumferentially directed wall, is formed on the end face (20) of the tool (18), on which the round blank (16) at least partly engages during securing.
9. Spinning device according to claim 6, 7 or 8, characterized in that a profiling for bringing about a positive engagement is formed on a circumferential side of the annular wall directed towards the round blank.
10. Spinning device according to one of the claims 6 to 8, characterized in that a retaining device constructed as a magnetic clamping device or a vacuum clamping device is provided on the tool for the at least partial clamping of the round blank.

Images