The invention embodiments disclosed relate generally to a method for producing an internally and externally toothed cup-shaped sheet material component with teeth that run in parallel to the center axis of the cup, in particular of a clutch plate carrier, and a corresponding device.
When manufacturing internally and externally toothed cup-shaped sheet material components, for example, cup-shaped clutch plate carriers or similar workpieces with a cylindrical basic structure, high accuracy and precision are required in their production. Particularly important is the accuracy of the true running while adhering to the cylindrical basic structure.
Thus, this involves high quality, cup-shaped sheet material components produced with a tooth-like shape on the inside and the outside which are primarily required in high numbers, also for automatic transmissions. Thus, in addition to quality features, low cost for producing the same is an important aspect for the concept of a production device for such sheet material components.
From German patent, DE 20 17 709, such a method for rolling longitudinal grooves into cylindrical workpieces is known, which method allows to form a wall profile of the sheet material component in a single operation by means of a press.
An adequately designed rolling tool can form a cup-shaped sheet material component (blank) in a single working stroke into an internally and externally tooth-like profiled finished profile. Here, with each press stroke, a rolling process on the sheet material component takes place, wherein a ring-shaped set of profile rollers rolls the desired external profile into the outside surface of the sheet material component.
For this, the set of profile rollers is positioned in the bottom tool of the device around the circumference of the sheet material component to be produced. The sheet material component is fastened in the upper tool by means of a pick-up mandrel. Upon actuation of the upper tool via the ram of the press, the cup-shaped sheet material component is pressed through between the set of rollers.
The profile rollers of the device itself have a relatively small diameter, wherein their axle pins are each supported toward the support ring side by two support rollers during the rolling process.
The support rollers are configured on top of each other in the vertical center plane of the respective profile roller but are inclined at an acute angle with respect to the horizontal, namely, for transferring the occurring rolling forces into the support ring.
Furthermore, the profile rollers can be individually radially preset toward the sheet material component or its pick-up mandrel, respectively, wherein this takes place at the respective receiving body by means of wedge pieces between the pair of support rollers and the outer support ring.
The profile rollers as well as each of their two support rollers are arranged in a single massive receiving body in such a manner that a relatively secure force transfer into the reinforcing ring can take place during the rolling process of longitudinal grooves into the cylindrical workpiece.
The receiving bodies for profile rollers and support rollers are arranged next to one another and spaced apart from one another thereby forming the ring-shaped set of profile rollers.
Thus, the bottom tool can be structured in a rotationally symmetric manner, wherein the profile rollers generating the profile of the sheet material component are regularly distributed and at a uniform angle to one another along the circumference of the sheet material component. Consequently and because of the resulting rotationally symmetric force distribution during the rolling process, the individual grooves produced by the respective profile rollers are virtually identical. In particular, a step-free contour is achieved.
A disadvantage of the method is that different sheet materials from different material batches can result in dimensional deviations with respect to the true running and on the surface. Furthermore, the adjustment of the tool to the specified dimension requires a significant amount of work and time during tool making or repair/maintenance.
Embodiments of the invention are thus based on a purpose to provide a method and a device in which the profile rollers, which control the true running, the dimensional accuracy, and the surface of the cup-shaped sheet material component having an internally and externally profiled wall in the shape of teeth, ensure a specifically variable position during the production process.
A purpose of embodiments of the invention is achieved, on the one hand, by a method for producing an internally and externally toothed cup-shaped sheet material with teeth that run in parallel to the center axis of the cup, an example being a clutch plate carrier. In this method, an untoothed cup-shaped sheet material component is slid onto a pick-up mandrel which has an external toothing corresponding to the internal toothing to be produced of the sheet material component and the external profile is then rolled onto the cup-shaped sheet material component by pressing the cup-shaped sheet material component together with the pick-up mandrel through a set of profile rollers rolling in parallel to the center axis on the sheet material component while exerting a radial pressure, thereby pressing the material into the tooth grooves of the pick-up mandrel. By this means, in the region of the open end of the cup-shaped sheet material component to be formed, a displacement of each profile roller of the set of profile rollers toward the pick-up mandrel takes place, whereby the desired profile of the forming internally and externally toothed region at the open end of the sheet material component is generated due to a pressure relief Removal of the sheet material component toothed in such a manner is then accomplished.
A purpose is further achieved by a device for producing an internally and externally cup-shaped sheet material component with teeth that run in parallel to the center axis of the cup, again, such as a clutch plate carrier. The device comprises a tool part with a circumferentially arranged set of profile rollers arranged concentric to the workpiece and have profile roller axes arranged transverse to the workpiece axis. A further tool part with a pick-up mandrel that has a tooth-like profiled outer contour for the sheet material component is also included, wherein the tool part with the set of profile rollers and the pick-up mandrel of the further tool part are formed to be coaxially movable with respect to one another. Each profile roller is arranged in a floating manner in a split bearing shell in a substantially rectangularly formed profile roller holder.
Embodiments of the invention are based on the idea to use the downwardly directed stroke of a forming press for a roll forming process within a tool in which, depending on the contour of the component, a multi-dimensional rolling along a rotary outer contour is possible. By the rollers which are movable during the stroke, dimensional deviations can be corrected and a subsequent finish grinding for achieving the desired tolerance on the sheet material component is not required during the fabrication of the device. This applies in particular to high components which, for example, in case of transmission parts, must be provided with the same highly speed-resistant shape as sheet material components with a low component height. Due to anisotropic properties of the sheet material, a critical ratio of component height to sheet material thickness can result in undesired, widened, that is, non-homogeneous, dimensional tolerance with respect to the workpiece diameter (tulip shape). Here, it is necessary to arrange the rollers according to calculated and incorporated contours during the forming not in a stationary manner with respect to the circumference of the sheet material component, but movable/adjustable so as to counteract this effect. A negative form of the pick-up mandrel for the sheet material component is to be considered here.
A method according to embodiments of the invention is thus based on the idea that an untoothed cup-shaped sheet material component is slid onto a pick-up mandrel which has an external toothing corresponding to the internal toothing to be produced of the sheet material component, and the external profile is then rolled onto the cup-shaped sheet material component by pressing the cup-shaped sheet material component together with the pick-up mandrel through a set of profile rollers rolling in parallel to the center axis on the sheet material component while exerting a radial pressure, thereby pressing the material into the tooth grooves of the pick-up mandrel.
According to embodiments of the invention, the method described above is completed in such a manner that in the region of the open end of the cup-shaped sheet material component to be formed, a displacement of each profile roller of the set of profile rollers toward the pick-up mandrel takes place, whereby the desired profile of the forming internally and externally toothed region at the open end of the sheet material component is generated due to a pressure relief and removal of the sheet material component toothed in such a manner.
An advantageous configuration of the described method is considered that toward the end of the tooth rolling process, each profile roller of the profile roller set is displaced during the tooth forming in radial direction in the range of 0.01 to 4 millimeters corresponding to the negative form of the mandrel.
The device for carrying out the method according to the invention embodiments is configured in such a manner that a tool part comprises a circumferentially arranged set of profile rollers, the profile rollers of which are arranged concentric to the sheet material component and have profile roller axes arranged transverse to the workpiece axis. Further, the tool part has a pick-up mandrel with a tooth-like profiled outer contour for the sheet material component, and the tool part having the set of profile rollers and the pick-up mandrel of the other tool part are formed to be coaxially movable with respect to one another. This basic design of the device is configured according to the invention in such a manner that each profile roller is arranged in a floating manner in a split bearing shell in a substantially rectangularly formed profile roller holder.
According to a preferred embodiment of the invention, a common wedge-shaped guide part can be provided between the profile roller holders and toward the holding ring, each profile roller holder can be configured to be radially adjustable by means of a wedge element in the direction toward the sheet material component to be formed.
As developments of the device are considered that a control of the wedge elements for radial adjustability in the direction of the sheet material component to be formed as well as the withdrawal of the same by ram elements arranged at the upper tool is provided.
A control of the wedge elements for radial adjustability in the direction toward the sheet material component to be formed can also be provided by means of servo-electric drives and depending on the stroke position. On the other hand, the radial adjustability can also be provided servo-hydraulically, depending on the stroke position and freely programmable.
In the above described embodiments of the device according to the invention it is particularly useful if by means of a pressurized lubrication, lubricant can be fed via a lubricant line to the profile rollers.
Moreover, it is of advantage in said variants if by means of a pressurized lubrication, lubricant for the respective adjusting mechanism can be fed via a lubricant line.
According to a further variant, the device according to the invention is configured in such a manner that each profile roller is configured to be movable in the direction toward the sheet material component to be formed.
In a further advantageous development of the invention, the profile rollers are configured to be movable during the downstroke of the ram in the radial direction toward the sheet material component to be formed and can be moved back in the starting position by means of an ejector or cushion/drawing mechanism of the press after/upon end of the stroke.
According to a further exemplary embodiment of the device according to the invention, each profile roller holder is formed as one piece.
According to a further variant of the invention, a plurality of devices according to the invention can be arranged one above the other.
The invention is further described below by means of the subsequent detailed description of advantageous embodiments of the invention, reference being made to the accompanying drawing, wherein:
With reference now to the drawing, and more particularly to
For the sake of clarity,
It is intended to show here how the process of a controlled roll forming of the tooth-like profile radially toward the forming profile is carried out to counteract, for example, a so-called tulip shape toward the outside by a deformation through roll forming as shown. The isometric view of finished toothed sheet material component 12.5 occurs after pressure relief and removal of the finished part. Thus, the required target profile of the toothed sheet material component is achieved. Corresponding sectional and profile views are shown by means of ejected finished toothed sheet material component 12.6.
Thus, a previous disadvantage of the prior art, namely the formation of a so-called tulip shape on internally and externally toothed cup-shaped sheet material components, can be specifically excluded. Furthermore, the true running and the surface quality can be positively influenced by a specific control of the radial displacement.
The tool part 18 with pick-up mandrel 20 for the cup-shaped sheet material component 12.1/12.2 is fastened on the ram of press 14 (
In
In
The end of the roll forming process of the toothing of the cup-shaped sheet material component 12.3/12.4 or 12.5/12.6, respectively, is finally illustrated in
Number | Date | Country | Kind |
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10 2008 017 608.7 | Apr 2008 | DE | national |
Number | Date | Country | |
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Parent | PCT/DE2009/000463 | Mar 2009 | US |
Child | 12899420 | US |