EP3323527A1 - Method and device for increasing the thickness of the edge of a sheet-metal body - Google Patents

Abstract

The invention relates to a device and a method for thickening the edge of a sheet metal body (2), in which the sheet metal body (2) clamped between the jaws (1a, 1b) of a Einspannwerkzeuges and about a rotation axis (3) perpendicular to its sheet plane continuously or incrementally is rotated and with a forming tool (4) a forming force in a direction perpendicular to the axis of rotation (3) on the edge (2a), in particular the edge end face is exerted, whereby edge material of the sheet metal body (2) is displaced in an axial and / or radial direction in which a forming tool (4) is placed in contacting contact with the sheet metal body (2) in a direction perpendicular to the axis of rotation (3), preceded by a limiting tool (5) in the adjustment direction, which forms a variable axial gap (5), in which the edge (2a) of the sheet metal body (2) rests and the axial gap dimension of the axial gap (5c) by e Ine axial relative movement between two axially opposite gap jaws (5a, 5b) of the limiting tool changed during the deformation, in particular is increased.

Description

The invention relates to a method for thickening the edge of a sheet metal body, in which the sheet metal body is clamped between the jaws of a Einspannwerkzeuges and continuously or incrementally rotated about a rotation axis perpendicular to its sheet plane and with a forming tool a forming force in a direction perpendicular to the axis of rotation on the edge , In particular, the edge end face is exerted, whereby edge material of the sheet metal body is displaced in an axial and / or radial direction. Preferably, the jaws provided for clamping are arranged around the axis of rotation, e.g. in this case formed circular disk-shaped, in particular wherein the axis of rotation passes through the circular disk center of the jaws.

The invention further relates to a device for producing an edge thickening on a sheet metal body, comprising a clamping tool with two axially opposing jaws, between which a sheet metal body clamped and about a rotational axis perpendicular to the sheet plane is continuously or intermittently rotatable and a forming tool that in a direction perpendicular is movable relative to the axis of rotation of the clamping tool relative to this, in particular in order to come into contact with the edge of a clamped sheet metal body and to exert on this a reshaping force and thereby axially and / or radially displace material.

By an intermittent rotation is meant that the clamping tool rotates the clamped sheet metal body by a predetermined angular amount and thereafter stands still for a time, in particular in this Downtime then make a transformation with the forming tool. For this purpose, the forming force is exerted on the edge during the downtime by the forming tool, by hiring the forming tool to the edge. In particular, for the next incremental rotation, the forming tool is first pulled away radially from the edge of the sheet metal again.

By continuous rotation is meant that the clamping tool rotates the workpiece without stopping over a predetermined angular range, in particular during which the forming force is applied to the edge of the sheet metal body during this rotation with the forming tool. The predetermined angular range preferably corresponds to the angular range over which the deformation zone extends on the sheet metal body, in particular, this angular range can be both smaller and greater than or equal to 360 degrees. Preferably, a rotationally symmetrical sheet metal body whose forming zone extends over 360 degrees rotates several times over 360 degrees until a deformation is completed.

Due to the axial displacement of material of the sheet metal body, in particular combined with a radial displacement, it is possible to thicken the edge of the sheet metal body beyond the original thickness of the sheet metal body with simultaneous decrease in the radial overall extent of the sheet metal body.

Such a method is from the previously filed, but post-published application DE 10 2015 015 388.9 the same applicant and is used there to connect individual sheets of a stacked sheet metal body with thickening of the edge of at least one individual sheet together.

The present invention can be applied to sheet metal bodies which are stacked from a plurality of individual sheets, as well as to sheet metal bodies which consist only of a single sheet.

In the context of the invention, the term "sheet metal" is understood to mean sheet-like elements made of metal or else of non-metal, usually in which the extent of the large, opposing surfaces is greater, in particular much greater, in one or two mutually perpendicular directions, preferably at least 10 times greater than the spacing of these two surfaces. A sheet thus has in at least one direction an extension which is at least 10 times greater than the measure that is usually understood as a thickness. A sheet can therefore be made for example by rolling.

A sheet metal body is a body comprising at least one such sheet.

The sheet plane of the sheet metal body is understood to mean the center plane, which is arranged centrally in relation to the thickness of the body in the one or more stacked sheets parallel to the large opposing surfaces.

All directions to which the present description refers are in relation to the axis of rotation of the clamping tool, unless expressly described otherwise.

Such a method or such a device is preferably provided in order to create a toothing at the edge of the sheet metal body after thickening or at the same time accompanying it. A subsequent subsequent gearing is often done by machining the thickened edge. A simultaneous creation is often made by a forming tool that has the negative mold of at least one tooth, if necessary. Of several teeth, so that the teeth are pressed in the edge material when the edge is thickened.

Benefits result from these methods in that teeth can be easily created even over a partial circumference of less than 360 degrees, or reshaped sheet metal body does not necessarily have to be 360 ° rotationally symmetric.

Typical fields of application are therefore, in addition to conventional gears, also curved toothed racks or levers with toothings, such as, for example, toothed racks. in seat adjusters of car seats.

The problem with this type of edge thickening is that the axial and / or radial geometric expansion of a thickening created is less controllable. The respective extent is essentially determined by the flow properties of the material. However, it is often desirable to be able to adjust the axial extent of a thickening and preferably also its radial extent in a controlled manner, especially in the production of toothings on the edge, e.g. in order to be able to set required load transfer characteristics of gears in a targeted and reproducible manner.

It is therefore an object of the invention to develop a possibility of axial control and preferably also the radial control of a thickening in such a generic method or the generic device by a development of the invention.

According to the invention, this is done in a method in that on the sheet metal body for exerting the forming force, a forming tool in a direction perpendicular to the axis of rotation is made contacting, which is preceded in Anstellrichtung a limiting tool that forms a variable axial gap in which the edge of the sheet metal body rests. The axial gap is understood to mean a gap which extends in the axial direction.

Furthermore, it is inventively provided that the axial gap dimension of the axial gap changed by an axial relative movement between two axially opposite gap jaws of the limiting tool during the forming, in particular is increased. These axially opposing gap jaws can preferably have an extension in the radial direction, so that the gap jaws each cover an edge region of the sheet metal body when it rests with its edge in the axial gap. For this purpose, the sheet metal body is preferably clamped by the clamping tool without covering a circumferentially extending, radially outer edge region of the sheet metal body by the jaws of the clamping tool, which comprises the deformation zone of the sheet metal body edge. Despite secure clamping so the deformation zone remains free of any overlap and thus accessible to the forming tool and the limiting tool.

With regard to the device, the object is achieved in that in the radial direction in front of the end face of the forming tool (as viewed in the direction of Einspannwerkzeug) a limiting tool is arranged, preferably which is movable together with the forming tool perpendicular to the axis of rotation of the Einspannwerkzeuges, which forms an axial gap, with the edge of a clamped sheet metal body is overlapped and the limiting tool has two axially opposing gap jaws which limit the axial gap in the axial direction and which are adjustable relative to each other in the axial direction to change the axial gap formed between them, in particular to change during a forming process.

The essential core idea of the invention is to give the axial evasive edge material an axial limit during the forming, which is given by the spacing of the facing jaws of the clamping tool. This also burrs on the shifted material can be prevented.

Preferably, the gap jaws can initially be set to a distance which is at least slightly greater than the sheet thickness, so that the edge of the sheet metal body to be formed can penetrate into the gap of the limiting tool. It may alternatively or in combination with the aforementioned embodiment also be provided that widens the gap formed in the radial direction and in the direction of the clamping tool. The radially outer gap with respect to the sheet metal body may initially coincide with the thickness of the sheet metal body.

Regardless of the specific current axial gap width and in particular regardless of whether this concrete gap initially present or passive during the forming is taken or active, in a force exerted by the end face of the forming tool on the edge of the sheet metal body in a direction perpendicular to the axis of rotation and preferred Thus, in the radial direction, material of the edge in the axial direction only deflected so far until it reaches the axially opposite surfaces of the gap jaws.

A further material flow is hereafter at least limited or even prevented, so that a flow of material takes place with further radial application of force even if only axially in the radial direction, if not even with axially held gap jaws. Thus, by e.g. active control of the gap jaws, so e.g. their targeted detention against axial adjustment or by a targeted axial adjustment can be made concrete influence on the axial and / or radial flow of material in a radial force exerted by the end face of the forming tool.

In a possible embodiment, the invention can provide that the clamping jaws of the limiting tool are displaced in the axial direction by the force exerted axially on the displaced edge material of the sheet metal body, in particular are displaced passively, preferably against a static or changeable application of force. Such a force application may e.g. by a passive Kraftbeaufschlagungsmittel, in particular at least one spring take place in a direction to reduce the axial gap. Instead of a spring and a compressible medium can be used.

Although an axial flow of the edge material is thereby limited by the splitting jaws, it is not prevented. The thickened edge can thus be easily adapted in terms of its shape to the shape of the gap of the restraint tool. By the counterforce, which counteracts the axial expansion is thus further achieved that at least a part of the material also flows in the radial direction. This passive displacement can generally be used to set a ratio of axial to radial thickening. Preferably, the invention can provide here, the counterforce that is generated by the gap jaws, so their power application to make variable adjustable.

The invention may alternatively provide that the axial distance of the gap jaws of the limiting tool are actively adjusted to each other by at least one actuator in the axial direction. For this purpose, the device may comprise at least one actuator, in particular comprise at least one actuator per gap jaw, in particular a hydraulically operated actuator with which at least one gap jaw is axially movable.

The relative movement of the gap jaws relative to one another is understood to mean that at least one slit jaw is movable relative to the other, preferably both are movable and particularly preferably both slit jaws are moved simultaneously, preferably with the same axial movement width, in particular for achieving an edge thickening symmetrical about the sheet plane.

The invention may also provide for adjusting the gap jaws in the axial direction relative to each other for changing the axial gap dimension as a function of the radial setting position of the forming tool. Depending on the radial position, e.g. are specified, whether the material is displaced primarily axially or radially with further application of force in the radial direction, or as the ratio of these two displacement options.

A change in the axial gap width of the gap of the limiting tool can be done stepwise, for example, before adjusting the gap jaws to a desired gap width, then the force exerted and the gap thus be filled by the displaced material, after which the first radial force application interrupted and the gap width is changed.

Alternatively, it may also be contemplated to increase the gap width continuously during the application of the radial forming force, e.g. by said active control. The ratio of radial feed of the forming tool and simultaneous axial opening of the gap of the limiting tool can preferably be changed.

In principle, the invention can provide that for forming only the clamping tool and thus the clamped sheet metal body intermittently or preferably continuously rotates. Apart from the radial infeed, the forming tool and the limiting tool can be stationary in the direction of the clamping tool, ie, in particular, they can not rotate themselves.

In general, in all, including the subsequent embodiments, the forming tool and the limiting tool can be connected in a common holder, thus be simultaneously movable.

Preferably, the invention provides that during a rotation of the sheet metal body / clamping tool about the rotation axis at the same time rotate the forming tool and the clamping jaws arranged around its around limiting tool around a parallel axis of rotation, in particular passive or preferably synchronously driven, more preferably with a variable gear ratio, wherein the edge of the sheet metal body and the end face of the forming tool assigned to the edge roll on one another.

This avoids that results in a significant friction between the edge of the sheet metal body and the end face of the forming tool. A warm-up is avoided. This is particularly advantageous when a toothing is pressed into the edge of the sheet metal body during the forming by the forming tool at the same time to create the edge thickening. In particular, the resulting strain hardening should be maintained with this design.

In order to achieve high stability, the invention may generally provide that a respective gap jaw comprises an area which is arranged in the radial direction in front of the end face of the forming tool, which faces the clamping tool and has an area which is arranged axially adjacent to the forming tool, in particular, a gap jaw in cross-section parallel to the axis of rotation L-shaped. Preferably, the region of the respective splitting jaw located in front of the end face contacts the end face.

Especially if, in addition to the clamping tool, the forming tool and the limiting tool also rotate, the invention provides that the forming tool and the clamping jaws of the limiting tool are circular disk-shaped and rotate about a common axis of rotation, preferably parallel to the axis of rotation of the clamping tool. The axes of rotation of the forming tool / limiting tool and the clamping tool can also be tilted relative to each other, in particular include an acute angle. As a result, a voltage superposition can be achieved and the radial deformation force can be reduced. The included acute angle is preferably greater than 0 and less than 10 degrees, more preferably greater than 0 and less than 5 degrees, even more preferably greater than 0 and less than 3 degrees. A gap jaw essentially corresponds to a circular disk with an outer, axially projecting edge, which forms the region which is arranged radially in front of the end face of the forming tool. In this embodiment, both gap jaws encompass the forming tool, which can be a simple disk, both axially and radially.

In a concretized embodiment, a respective gap jaw can be rotatably arranged on an axially adjustable in the position of a plate holder of the forming tool, wherein the respective plate is axially driven with at least one, preferably two actuators.

A respective gap jaw is preferably exactly linearly parallel to the axis of rotation adjustable, which can be preferably realized by said at least two actuators or by displaceability in a linear guide.

Furthermore, the axis of rotation of the forming tool / limiting tool and the axis of rotation of the clamping tool can be synchronously coupled to each other via a gear, in particular, the forming tool / limiting tool can be driven by a drive of the clamping tool. The transmission ratio of the transmission can preferably be changed.

For example, Such a change can be provided if, with simultaneous edge thickening and pressing in of teeth into the edge of the sheet metal body, the (negative) teeth-comprising forming tool, while the circumference remains constant, is made radially further on the sheet metal body becoming smaller in circumference.

Embodiments will be described below with reference to the figures.

FIG. 1 shows an embodiment of a device with a continuously rotated clamping tool 1, in the jaws 1 a and 1 b, a sheet metal body 2 is clamped and is rotated about the rotation axis. 3

In a direction radial to the axis of rotation 3, a forming tool 4 is set against the edge of the sheet metal body, so that the end face 4a of the forming tool 4 radially contacts the edge of the sheet metal body 2 and exerts a radial deforming force thereon.

To the forming tool 4, a limiting tool is arranged, that has two split jaws 5a and 5b. The gap jaws enclose the forming tool axially and radially. Between the gap jaws 5a, 5b, an axial gap 5c is formed, into which the edge 2a of the sheet metal body 2 extends. To facilitate this, the gap 5c extends radially in the direction of the clamping tool 1. This initial position is in the FIG. 1 shown above.

Center in the FIG. 1 the end position of the transformation is visualized. The forming tool has been delivered radially relative to the starting position on the clamping tool and thus on the sheet metal body 2. Material from the edge 2a has been displaced axially and has here, for example, the passive force-biased gap jaws 5a and 5b in the axial direction against the biasing force. Alternatively, the gap jaws 5a, 5b were controlled by actuators moved and / or detained.

As a result of the displacement, the gap 5c increases in the axial direction, which allows the edge thickening, but limits or contoured the material. In particular, it has been achieved by the restriction that the material flows not only axially but also radially.

The lower area of the FIG. 1 shows the top view and illustrates a non-rotating forming tool 4 or limiting tool 5, which is only moved radially, in particular together.

In this version of the FIG. 1 the clamping tool can rotate the sheet metal body continuously and the end face of the forming tool is rounded flat or in a plane parallel to the sheet plane.

FIG. 2 On the other hand, an embodiment in which the clamping tool is intermittently rotated, that is, alternately rotated and stopped, to perform a deforming step.

With each forming step, a toothing is pressed into the edge 2a of the sheet metal body with the forming tool having a negative toothing 6 at the end. Start position (top) and end position (middle) correspond to the positions of the restraint tool, as it is for FIG. 1 has been described. In this case, the radially assigned to the end face of the forming tool surface of each gap jaw also have a toothing, which engages in the spur toothing of the forming tool. This applies to all versions in which teeth are produced, including the later FIG. 4 ,

FIG. 3 shows an embodiment in which the forming tool 4 and the gap jaws 5a, 5b of the limiting tool also rotate and are each disc-shaped. In the rotation about the parallel axes 3 and 7, the tools are synchronized.

In the same way, as the edge deformation progresses, the gap 5c is increased in its axial width, thus allowing an axial flow of the material, but limiting it, in particular if the gap jaws are held in an actuator.

According to the plan view, the end face 4a of the forming tool and the edge 2a of the sheet metal body 2 roll on each other, which prevents heating. Preferably, the tools 4 can roll freely here, ie without drive or synchronization with the clamping tool.

In the FIG. 4 is the difference to FIG. 3 in that the end face 4a of the forming tool has a circumferentially completely extending (negative) toothing. By way of rolling on the edge 2a of the sheet metal body and the radial feed on this to a toothing rolling in pressed into the edge during rolling. For this, the rotations of the tools 4/5 and 1 are synchronized with each other, for example via a common transmission.

Claims (14)

Method for thickening the edge of a sheet-metal body (2), in which the sheet-metal body (2) is clamped between the jaws (1a, 1b) of a clamping tool and is rotated continuously or incrementally about a rotation axis (3) perpendicular to its sheet plane and with a forming tool ( 4) a deformation force in a direction perpendicular to the axis of rotation (3) on the edge (2a), in particular the edge end face is exerted, whereby edge material of the sheet metal body (2) is displaced in an axial and / or radial direction, characterized in that a. to the sheet metal body (2) for exerting the forming force a forming tool (4) in a direction perpendicular to the axis of rotation (3) is made contacting, in front of the Anstellrichtung a limiting tool (5) that forms a variable axial gap (5), in which the edge (2a) of the sheet metal body (2) rests and b. the axial gap dimension of the axial gap (5c) is changed, in particular increased, by an axial relative movement between two axially opposing gap jaws (5a, 5b) of the delimiting tool during the deformation. A method according to claim 1, characterized in that the gap jaws (5a, 5b) of the limiting tool are displaced axially by the force exerted by the displaced edge material of the sheet metal body (2) in this axial force, in particular passively displaced, preferably against a static or changeable application of force. A method according to claim 1, characterized in that the axial distance of the gap jaws (5a, 5b) of the limiting tool to each other by at least one actuator in the axial direction are actively adjusted. A method according to claim 2 or 3, characterized in that both gap jaws (5a, 5b) are moved simultaneously, preferably with the same axial movement distance, in particular for achieving a symmetrical about the sheet plane edge thickening. Method according to one of the preceding claims, characterized in that the gap jaws (5a, 5b) are adjusted in the axial direction relative to each other to change the Axialspaltmaßes depending on the radial setting position of the forming tool (4). Method according to one of the preceding claims, characterized in that at a rotation of the sheet metal body (2) / clamping tool (1) about the rotation axis (3) at the same time the forming tool (4) and with its gap jaws (5a, 5b) arranged around it Rotate limiting tool about a particular parallel axis of rotation (7), in particular passively or preferably synchronously driven, more preferably with a variable gear ratio, wherein the edge (2a) of the sheet metal body (2) and the edge (2a) assigned end face (4a) of the forming tool (4) roll on each other. Method according to one of the preceding claims, characterized in that during the forming by the forming tool (4) at the same time for creating the edge thickening a toothing in the edge (2a) of the sheet metal body (2) is pressed. Device for producing edge thickening on a sheet metal body (2), comprising a. a Einspannwerkzeug with two axially opposite jaws (1a, 1b), between which a sheet metal body (2) is clamped and about a rotation axis (3) perpendicular to the plane continuously or intermittently rotatable and b. a forming tool (4) movable in a direction perpendicular to the rotation axis (3) of the clamping tool (1) relative thereto, in particular to come into contact with the edge (2a) of a clamped sheet metal body (2), characterized in that c. in the radial direction in front of the end face (4a) of the forming tool (4) a limiting tool (5) is arranged, preferably which together with the forming tool (4) perpendicular to the rotation axis (3) of the clamping tool is movable, which forms an axial gap (5c), with the edge (2a) of a clamped sheet metal body (2) is overlapped and d. the limiting tool (5) has two axially opposing gap jaws (5a, 5b) which delimit the axial gap (5c) in the axial direction and which are adjustable relative to each other in the axial direction for changing the axial gap formed between them. Apparatus according to claim 8, characterized in that the gap jaws (5a, 5b) in the axial direction by a passive Kraftbeaufschlagungsmittel, in particular at least one spring kraftbeaufschlag are in a direction to reduce the axial gap. Apparatus according to claim 8, characterized in that it comprises at least one actuator, in particular each gap jaw (5a, 5b) comprises an actuator, in particular a hydraulically operated actuator with which at least one gap jaw (5a, 5b) is axially movable. Device according to one of the preceding claims, characterized in that a respective gap jaw (5a, 5b) comprises a region (5a2) which is arranged in the radial direction in front of the end face (4a) of the forming tool (4), which is the clamping tool (1). has and a region (5a1), which is arranged axially adjacent to the forming tool (4), in particular a split jaw (5a, 5b) is formed in cross-section parallel to the axis of rotation L-shaped. Device according to one of the preceding claims, characterized in that the forming tool (4) and the gap jaws (5a, 5b) of the limiting tool (5) are formed circular disk-shaped and about a common axis of rotation (7) are rotatable, in particular parallel or in an acute Angle to the axis of rotation (3) of the clamping tool (4). Apparatus according to claim 12, characterized in that a respective gap jaw (5a, 5b) is rotatably disposed in a positionally axially adjustable plate of a holder of the forming tool (4), wherein the respective plate with at least one, preferably at least two actuators axially driven is. Device according to one of the preceding claims, characterized in that the axis of rotation (7) of the forming tool (4) / limiting tool (5) and the axis of rotation (3) of the clamping tool (1) via a transmission synchronously coupled to each other, in particular thereby the forming tool (4) / limiting tool (5) by a drive of the clamping tool (4) is driven.

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